I love that you showed the failed experiment with the skateboard and fire extinguisher, failure does not mean the science is bad, it might means the engineering is bad. The reverse is also true, bad engineering can lead to validation of bad science, like the many peoples that think they have achieved free energy/perpetual motion. I'm thinking of the people who genuinely believe they have achieved those things, not the scammers.
OMG 2:41 That is one of the most gorgeous photographs of a Sukhoi I have EVER seen. The camera angle, the colors, the visible condensation in the wingtip vortex, man it's perfect!!!
One thing you forgot to mention, that is making WaterJet slightly better than a regular jet. The thrust generated by water going down is not the only thrust you get. Water coming up to you also carry a momentum pointed vertically UP. And as it get a momentum pointed down, is has to give YOU it's former UP momentun first.
You're trying to explain to me how "Rocket science is one of the most complicated.....", but I'm too distracted by you merrily floating around with a huge grin on your face and a jetpack strapped to your back.
Actually the science behind rockets is quite simple which is what he was conveying in this video. Rocket science of figuring out how to use rockets for traversing through space. You can make a rocket out of common household products like matches and aluminum foil so the science behind how rockets work isn't that complex.
They actually do have some throttle - they reduce the power down to 70% to limit max stress on the craft as they're accelerating through dense atmosphere
You have to get up to speed by the time you reach orbit so you don't really have much choice. But 3g's is not so bad that you'd really risk blacking out
This is probably the best video you've ever made. The video is in my opinion the perfect length, and the narrative and visuals are just excellent. Lastly, it's very inspirational and makes you curious to find out more. Great job Derek, keep it up!
Quality stuff as always! :) However you did say that most of the acceleration of a space shuttle in orbit is horizontal. I think it needs o be noted that this true for its ascent but not for orbit. I understand that this video isn't supposed to go too deep into the topic, but to be in orbit, the space shuttle experience a vertical (centripetal) acceleration of 1g. If it accelerated horizontally once in orbit, it would leave orbit. It accelerates horizontally UNTIL it is in orbit.
This guy is over-structured. After a few minutes into, the first viewing of this video my eye's glazed-over. So,much in fact that, I had bucking of tears squirting from my eye sockets and the last thing I remember were sparks all over the place. After I got out of the hospital with 3rd degree burns do to the electrical fire- I vowed to write this review on my new computer.
Overrated. Go ride a greyhound bus then make the seats smaller by %20 and make the windows really really small then remove your ability to get out of seat and go to bathroom when you want because the isle is so narrow. Commerical airplane travel is horrible. and don't forget to throw in if the plane breaks then you die.
To help clarify what he meant by F=(m-dot)*v, think about the units. m-dot is the rate of mass, as he mentioned, and would have the units kg/sec. This describes the rate of mass ejected from the fire extinguisher. To describe a force, this rate of mass must be multiplied by velocity, rather than acceleration, because 1 (kg/s)*(m/s) = 1 kg*(m/s^2) = 1 Newton. The dot is a notation used to describe the derivative. Hope this helps. :)
Was just picturing the converstion: Other Person: "Damn mate, what happened to your face?" Derek: "Well, i collided with a jetski while flying my jetpack."
1. GREAT video 2. AWESOME explanation 3. I want one of these 4. THANKS for nothing , cause now my brain hurts from all this info 5. hope your lip feels better 6. repeat step 1 & 3 as needed
They way vsauce goes off topic is very planned out. They cover things that are related to the main question and I very much enjoy the way he bridges the questions together
Why don't they build an elevated platform on the top of a mountain to launch rockets into space? Each additional meters seem to be extremely expensive…
One thing is... mountains tend to have slightly greater Gravity around them... but that is actually neglectable... Or at least not that important as having less air to cut through. Mostly that is not reasonable, because before launching something from atop a mountain, you have to DRAG all this stuff UP to a mountain. Do you have any idea how much rocket boosters weight? And they ususally are something you can not cut into parts and re-assemble on the launchpad. All that extra cost really outweights the cost of extra-fuel you have to burn to cut through atmosphere. ((Though
***** The problem is both distance and speed (& acceleration)… The closer you are to destination, less fuel is needed. (And less fuel is needed to bring the extra fuel… A thing usually underestimated!)
***** You might be surprised, but most of fuel (like 2/3 in case of Shuttle launch) is burned before a rocket starts gaining any orbital speed. Thick atmosphere generates a ton of friction (a.k.a. Air resistanse) and that means that exiting thick atmosphere a.s.a.p. is a good idea. And the bes way to exit atmosphere is to go straight up and then ditch the accent stage and burn insertion stage.
Force is actually the rate of change of the momentum of the centre of mass of your object, where momentum is P=mv. So, force is actually = d(ma); [d indicates the rate of change or "first order derivative" of the variables]; So, I believe that you can't really negate the effect of pressure that contributes towards the velocity, i.e., the velocity of the exhausted gas changes reduces as the pressure in the chamber falls.. So, I believe that the equation shown should have been *F=**_d_**(mv)*
If you redesigned this machine to recycle the water that was expelled and fed back into the intake, could this fly independently? You could add a turbocharger type device to a) increase the pressure of the water going in and b) slow the speed of the water coming out so that it doesn't counteract the thrust. Can anyone please explain if this wouldn't work and why? Thanks.
It wouldn't work. It would be like bringing a box fan onto a sail boat and trying to create your own wind. While the wind hitting the sails would act to push the boat forward, the fan itself would create an equal amount of thrust in the opposite direction counteracting the push from the wind. The same kind of logic would apply to your scenario. While the water being expelled out of the jet nozzle would provide thrust, it would ultimately be redirected back into the intake, and that process would create forces that counteract that thrust, and you'd net to zero. In other words, the very act of slowing the water down in order to bring it back into the intake would create a force in the opposite direction negating the thrust.
Willoughby Krenzteinburg Gotcha, thanks. I was hoping to dispel some of the energy somehow before it reaches whatever mechanism is drawing it back in, but I guess not being able to create or destroy energy would apply. Thank you for your reply.
Willoughby Krenzteinburg Gotcha, thanks. I was hoping to dispel some of the energy somehow before it reaches whatever mechanism is drawing it back in, but I guess not being able to create or destroy energy would apply. Thank you for your reply.
F=ma. Therefore, if you change the subject by dividing both sides by "m", you get F/m=ma/m, where the m's on the right side cancel out to give you F/m=a.
Nerds dont even need to invent. They are fun loving curious people who have a sense of adventure. We want to help people enjoy life, rather than put them down.
The trouble with getting to space isn't that it's far away... it's frighteningly close from a certain perspective... it's that in order to stay in space once you get there, you need to be moving at orbital speed. The earth is spinning, and the fastest part of the earth is the equator. So being close to the equator is of greater benefit than being up a mountain.
So i was watching a dude pull an axe off of his motorcycle and almost attack someone honking at him. Somehow this was a related video... I am now subscribed ^_^
"it's a pretty incredible experience" watching this video. :) also,thank u for clearing the "atmosphere pushing" misconception-which had that before this vid.
The m-dot as part of the formula he described was the "rate of mass". It's the derivative of mass and its units would be kg/sec. This would satisfy F=ma. I hope that explains everything.
Speaking of common misconceptions, the retardant leaving the extinguisher does not make you go forward. The previously balanced pressure inside of the extinguisher becoming imbalanced as the valve is opened makes you go forward.
Light is a wave. Waves behave differently. It's a form of energy, measured in joules. Light is also measured in candelas for intensity. If you really want to find the mass of light then you just use the famous E = mc^2 equation to find the mass of this light. E/c^2 = mass of light dependent on the amount of energy you have to begin with.
Think the nozzle should be explained a little more. The nozzle increases the velocity of the fluid, converting internal energy into kinetic energy, lending itself to a higher momentum force at the nozzle. Along with the increased velocity at the nozzle exit, yielding a lower pressure than right before the nozzle, also giving an upward force. Nozzles are what makes all this possible
KSP isn't a total simulator though. It has the principle of mass decreases so acceleration increases while thrust stays the same, but it was made to be a fun game while showing that space is beautiful, not to be a total simulator.
Acceleration can be a neutral constant, providing enough force versus resistance (gravity) to equal 0. Therefore, hovering or maintaining a position relative to another object or place. (I hope I explained it right!!).
too bad those kids thought the fire extinguishers can push your mass forward. now put those back where they belong to save lives as they meant to put out fires and get a real Jet Blaster. Don't try 100 Fire extinguishers. the mass gets bigger.
Actually what's interesting is that as you go up out of earth's gravity, the force of it actually lessens. So not only does the weight of the fuel change by the amount used, it also changes by the height of the rocket itself.
for those who thought f=m.v when he was talking about the rocket, the v here is the final velocity of the particles, their initial velocity was zero, so the particles are accelerated from 0 to v almost instantly(say about 1 sec at the most, but actually it would be lesser) so f=m(v-0)/t= m.(v)/1=m.v .
That is a good point but I heard an explanation some thing like higher altitude equals higher gravitational pull so it would require more force from the rocket to take off and gain speed. I don't know if that's right might be just because they don't like the cold weather on top of a mountain...
YES! I had a Toy as a good that was a balloon thing hooked up to water spouts - which you plugged into your garden hose. it was the coolest thing ever! I have often daydreamed about having one again, heh -- and about a human sized one like this. Awesome
One thing you should never do is put your arm, hand, legs or any body part infront of that water stream, you could really hurt yourself. You can even hurt yourself at the self car wash water blaster, imagine how much more powerful this water stream is. Reuse, reduce, recycle. Protect yourself and protect life.
That is correct. However, in instances where the instantaneous change in mass is equivalent to the average change in mass, you could use either m(dot) or (delta)m. I oversimplified a bit, I suppose.
the m they use refers to the change in mass over time. a is just the change in velocity over time. so instead of changing the velocity over time, they changed the mass over time. its still force.
3:30 - Even better, the thrust actually slightly increases, because the Isp (specific impulse) will increase as atmospheric pressure decreases, while fuel flow remains roughly constant. Even more g's for the astronauts :-)
I'm a couple years late but anyway, 3:10 the force in the rocket is not 5-8m/s but 15-18m/s, you have to add the gravitation. Also a free falling object has actually a acceleration of 0, not 9.81. It's only realtive to an observer 9.81, in truth, not the falling object is accelerated, but rather the observer standing on the ground is accelerated upwards. This is the concept of relativity and matters especially in the context of g-forces exerted on human bodies.
When you are dealing with things on Earth, the difference between Newtonian gravity and relativistic gravity is semantics. There is no real useful difference. You are also conflating acceleration and force. The 5-8 m/s² is indeed the acceleration. You don't add the acceleration of Earth. You would for the purposes of G-Force, like you said, but again - you don't have to apply General Relativity to compute G-Force.
About the trust of the jet pack... I think that the majority of the trust does not come from the water passing through the curve that redirects the water from going up to going down. If the water would be fed in from the top of the unit, you would probably still be lifted out of the water. So I think there is something else that provides the trust. My guess is that the water is accellerated because the the nozzle has a smaller diameter than the main tube. The acceleration exerts a force on the unit according to f=m*a and that's the main force that lifts you out of the water...
The principle is simple enough: "Push stuff one way so that you go the other way." The difficulty is the engineering--making it work in a controllable manner.
Please make a video about random numbers. You could include ERNIE the first true random number. And you could explain the differnce between true random and pheurandom numbers.
Don’t Rockets also go faster the higher they are because of less air resistance due to decreased air density so that also explains the exponential curve
I see where you are coming from, and I understand your confusion; I was a bit thrown for a second at first as well. What he actually wrote was F = (m dot) times v , where m dot stands for rate of mass expulsion (kg/s) rather than just plain old m, which stands for mass (kg). With m dot, the units work out, because force in Newtons is (kg m/s^2) and m dot times v is (kg/s) times (m/s), so you end up with (kg m/s^2). :)
Rocket science is really, really simple. The difficult part is rocket engineering. Trying to get an appreciably sized payload to orbit or wherever else without running out of fuel is the tough part.
very neat stuff, but i wish the physics was correct. In the beginning, F=ma, not F=mv. When talking about the space shuttle reaching orbit the comment, which is something like "most of the acceleration in orbit is horizontal", is incorrect. As it reaches orbit, its velocity becomes constant and all the acceleration is towards the center of the earth...as it FALLS around the Earth. No real biggy unless little Billy is using this for a physics report. Still a fun vid and nicely produced, etc.
Billions of micro organisms passing through the hose and pump had awesome roller coaster ride.
ikr
Xiaoke Ding lol
High-pressure probably killed them all!!!
@@shitbox10yearsago65 For related "Science" click on my name!!!
@@kareemsalessi no
I love that you showed the failed experiment with the skateboard and fire extinguisher, failure does not mean the science is bad, it might means the engineering is bad. The reverse is also true, bad engineering can lead to validation of bad science, like the many peoples that think they have achieved free energy/perpetual motion. I'm thinking of the people who genuinely believe they have achieved those things, not the scammers.
@@Macsuckks yes you have mentioned their username
OMG 2:41 That is one of the most gorgeous photographs of a Sukhoi I have EVER seen. The camera angle, the colors, the visible condensation in the wingtip vortex, man it's perfect!!!
Looks like a render. Hope it's not though
@@TikhonSuslov it could be the jet flying past a drone with a very good camera
"It's usually a good idea, unless you're in the path of a jet ski." And I the only one that flinched?
*Y E S*
yes...
I don't see what's soo damn great about it, Chuck Norris does this every time he pisses.
One thing you forgot to mention, that is making WaterJet slightly better than a regular jet.
The thrust generated by water going down is not the only thrust you get. Water coming up to you also carry a momentum pointed vertically UP. And as it get a momentum pointed down, is has to give YOU it's former UP momentun first.
Wrong. That's not how it works. There is no water with momentum coming up towards him.
Holy crap the guy riding the fire extinguisher cart at 1:44 was my physics professor! Shoutout to Mike Young
The force is strong with this one.
It's not upwards, it's horizontal - and at that point I imagine you're 'falling' vertically. It's on the NASA graph if you look carefully.
this reminds me of F.L.U.D.D from super mario sunshine
When I use my phone, I experience 4g force. How about that.
LOL you made my day x'D
Here in India we wait for cheaper 2G and reasonable 3G rates...
LOL
LOL
Alexandre Boucher LOL Props on that one.
You're trying to explain to me how "Rocket science is one of the most complicated.....", but I'm too distracted by you merrily floating around with a huge grin on your face and a jetpack strapped to your back.
Actually the science behind rockets is quite simple which is what he was conveying in this video. Rocket science of figuring out how to use rockets for traversing through space. You can make a rocket out of common household products like matches and aluminum foil so the science behind how rockets work isn't that complex.
yep exactly. Yep exactly. Yep exactly. Yep exactly. Yep exactly. Yep exactly. Yep exactly. Yep exactly. Yep exactly. Yep exactly.
They actually do have some throttle - they reduce the power down to 70% to limit max stress on the craft as they're accelerating through dense atmosphere
You have to get up to speed by the time you reach orbit so you don't really have much choice. But 3g's is not so bad that you'd really risk blacking out
Super Mario Sunshine.
I was about to say that!
This is probably the best video you've ever made. The video is in my opinion the perfect length, and the narrative and visuals are just excellent. Lastly, it's very inspirational and makes you curious to find out more. Great job Derek, keep it up!
thank you for making science SOOO fun:)
Quality stuff as always! :) However you did say that most of the acceleration of a space shuttle in orbit is horizontal. I think it needs o be noted that this true for its ascent but not for orbit. I understand that this video isn't supposed to go too deep into the topic, but to be in orbit, the space shuttle experience a vertical (centripetal) acceleration of 1g. If it accelerated horizontally once in orbit, it would leave orbit. It accelerates horizontally UNTIL it is in orbit.
I love people that spread knowledge, thank you.
"You just kinda need to trust that the jetpack will get you out of any trouble."
I will live by this.
SUPER MARIO SUNSHIIIIINE!
woohoo!
He sorta reminds me of the Property Brothers...Great video
6:48 is priceless haha! Bet that jet ski wiped that smile off your face.
This guy is over-structured. After a few minutes into, the first viewing of this video my eye's glazed-over. So,much in fact that, I had bucking of tears squirting from my eye sockets and the last thing I remember were sparks all over the place. After I got out of the hospital with 3rd degree burns do to the electrical fire- I vowed to write this review on my new computer.
+Veritasium Thanks for risking your bright shiny teeth for making this video.
what does Jetski taste?
Corn.
EpelepticMoon Blood
jetski
_Blood_
Great Channel! glad i discovered this..
You certainly have a great sense of humor. And great teeth too. So glad you didn't lose them. funny and fun.
7:31 AHH! Derek has a second head!
"You know the feeling when you take off on a plane?"
Cant relate😢
Oo thats deep
Overrated. Go ride a greyhound bus then make the seats smaller by %20 and make the windows really really small then remove your ability to get out of seat and go to bathroom when you want because the isle is so narrow.
Commerical airplane travel is horrible.
and don't forget to throw in if the plane breaks then you die.
To help clarify what he meant by F=(m-dot)*v, think about the units. m-dot is the rate of mass, as he mentioned, and would have the units kg/sec. This describes the rate of mass ejected from the fire extinguisher. To describe a force, this rate of mass must be multiplied by velocity, rather than acceleration, because 1 (kg/s)*(m/s) = 1 kg*(m/s^2) = 1 Newton. The dot is a notation used to describe the derivative. Hope this helps. :)
Was just picturing the converstion:
Other Person: "Damn mate, what happened to your face?"
Derek: "Well, i collided with a jetski while flying my jetpack."
Dear Santa...
when i clicked veritasium 2 it sent me to a website called buy instagram followers XD
lol me too ??
lol
yep I think that's the problem with really short urls(idk tho)
xD
1. GREAT video
2. AWESOME explanation
3. I want one of these
4. THANKS for nothing , cause now my brain hurts from all this info
5. hope your lip feels better
6. repeat step 1 & 3 as needed
They way vsauce goes off topic is very planned out. They cover things that are related to the main question and I very much enjoy the way he bridges the questions together
Why don't they build an elevated platform on the top of a mountain to launch rockets into space? Each additional meters seem to be extremely expensive…
One thing is... mountains tend to have slightly greater Gravity around them... but that is actually neglectable... Or at least not that important as having less air to cut through.
Mostly that is not reasonable, because before launching something from atop a mountain, you have to DRAG all this stuff UP to a mountain. Do you have any idea how much rocket boosters weight? And they ususally are something you can not cut into parts and re-assemble on the launchpad. All that extra cost really outweights the cost of extra-fuel you have to burn to cut through atmosphere. ((Though
Павел Жданов I think what you say is only a hypothesis… It may be wright, but I am not convinced…
The problem for a rocket is not going up. It is going fast enough to achieve an orbit, they need to get 7/8 km/s for a LEO for example !
***** The problem is both distance and speed (& acceleration)… The closer you are to destination, less fuel is needed. (And less fuel is needed to bring the extra fuel… A thing usually underestimated!)
***** You might be surprised, but most of fuel (like 2/3 in case of Shuttle launch) is burned before a rocket starts gaining any orbital speed.
Thick atmosphere generates a ton of friction (a.k.a. Air resistanse) and that means that exiting thick atmosphere a.s.a.p. is a good idea. And the bes way to exit atmosphere is to go straight up and then ditch the accent stage and burn insertion stage.
4:19 "Stacked on top of you - OHH OHH YEAH - hey how're you DOWN BELOW HUH? - AH you guys ARE HEAVY, OH MAN PHEW" #HaHGayyyyyyyyyyyyyyyy
xD I was waiting for this comment to po up LOL
+Diego Pomares i was certain there would be a genius to point out
Force is actually the rate of change of the momentum of the centre of mass of your object, where momentum is P=mv. So, force is actually = d(ma); [d indicates the rate of change or "first order derivative" of the variables]; So, I believe that you can't really negate the effect of pressure that contributes towards the velocity, i.e., the velocity of the exhausted gas changes reduces as the pressure in the chamber falls.. So, I believe that the equation shown should have been
*F=**_d_**(mv)*
That intro of him trying the water jetpack is the greatest thing I've ever seen.
F=mv isn't correct. It's supposed to be F=ma
Yes it is correct, he is referring to the force due to momentum
It's F = dm/dt * v, that's what the dot means.
+Matt Levonian Newton's 2 law
If you redesigned this machine to recycle the water that was expelled and fed back into the intake, could this fly independently?
You could add a turbocharger type device to a) increase the pressure of the water going in and b) slow the speed of the water coming out so that it doesn't counteract the thrust.
Can anyone please explain if this wouldn't work and why?
Thanks.
It wouldn't work. It would be like bringing a box fan onto a sail boat and trying to create your own wind. While the wind hitting the sails would act to push the boat forward, the fan itself would create an equal amount of thrust in the opposite direction counteracting the push from the wind.
The same kind of logic would apply to your scenario. While the water being expelled out of the jet nozzle would provide thrust, it would ultimately be redirected back into the intake, and that process would create forces that counteract that thrust, and you'd net to zero. In other words, the very act of slowing the water down in order to bring it back into the intake would create a force in the opposite direction negating the thrust.
Willoughby Krenzteinburg Gotcha, thanks.
I was hoping to dispel some of the energy somehow before it reaches whatever mechanism is drawing it back in, but I guess not being able to create or destroy energy would apply.
Thank you for your reply.
Willoughby Krenzteinburg Gotcha, thanks.
I was hoping to dispel some of the energy somehow before it reaches whatever mechanism is drawing it back in, but I guess not being able to create or destroy energy would apply.
Thank you for your reply.
Because the intake would slow down the water, and therefore the device, thus, instead of a rocket, it becomes more like a wheel.
There would be a force downward on the intake which would cancel out the upward force therefore, no flying
I wish my math teacher would have been this fun, maybe I would have had the math skills to understand more of the science I love :)
If ever granted the opportunity, I am most definitely doing that in this life time!
5:33 look at his eyes *hits weed*
Super Mario Sunshine, anyone?
Dylan Nylan yes!
When I was a kid I wanted to be an astronaut. Now I'm afraid of height and water.
Fun to watch the videos! thanks
4:26 I really enjoyed that 😂😂😂
F=ma. Therefore, if you change the subject by dividing both sides by "m", you get F/m=ma/m, where the m's on the right side cancel out to give you F/m=a.
Nerds dont even need to invent. They are fun loving curious people who have a sense of adventure. We want to help people enjoy life, rather than put them down.
The trouble with getting to space isn't that it's far away... it's frighteningly close from a certain perspective... it's that in order to stay in space once you get there, you need to be moving at orbital speed.
The earth is spinning, and the fastest part of the earth is the equator.
So being close to the equator is of greater benefit than being up a mountain.
Great job keeping it simple yet very informative. My 9 yr old can now boast about the physics of rocket science!! Thanks!!
had to share as I saw homeschooling friend Kelly at kidsmarket--we love science
Love the C02 experiment!
Shoosh with your dialogue and just give me the jet pack already! LOL.. so fun!
I love how he sees himself failing with humour that's how u really need to approach things !!! gj
So i was watching a dude pull an axe off of his motorcycle and almost attack someone honking at him. Somehow this was a related video... I am now subscribed ^_^
the best part of this video was learning that if someone goes down fast enough theres a redout
"it's a pretty incredible experience" watching this video. :)
also,thank u for clearing the "atmosphere pushing" misconception-which had that before this vid.
Great post. I really like ur way of explaining simple stuff.
The m-dot as part of the formula he described was the "rate of mass". It's the derivative of mass and its units would be kg/sec. This would satisfy F=ma. I hope that explains everything.
This video was AWESOME!!! I love videos that are fun and educational. Keep posting because these are the best!
Speaking of common misconceptions, the retardant leaving the extinguisher does not make you go forward. The previously balanced pressure inside of the extinguisher becoming imbalanced as the valve is opened makes you go forward.
Probably this will be only comment about your sound design..
amazing sound design
Light is a wave. Waves behave differently. It's a form of energy, measured in joules. Light is also measured in candelas for intensity. If you really want to find the mass of light then you just use the famous E = mc^2 equation to find the mass of this light. E/c^2 = mass of light dependent on the amount of energy you have to begin with.
Think the nozzle should be explained a little more. The nozzle increases the velocity of the fluid, converting internal energy into kinetic energy, lending itself to a higher momentum force at the nozzle. Along with the increased velocity at the nozzle exit, yielding a lower pressure than right before the nozzle, also giving an upward force. Nozzles are what makes all this possible
Closest? Okay, how was that not flying? honestly that was brilliant!
KSP isn't a total simulator though. It has the principle of mass decreases so acceleration increases while thrust stays the same, but it was made to be a fun game while showing that space is beautiful, not to be a total simulator.
This man teaches me things I never would have learned in my life...
They should show this video in science class.. I learned more from this video than I did in science class lol
Acceleration can be a neutral constant, providing enough force versus resistance (gravity) to equal 0. Therefore, hovering or maintaining a position relative to another object or place. (I hope I explained it right!!).
too bad those kids thought the fire extinguishers can push your mass forward. now put those back where they belong to save lives as they meant to put out fires and get a real Jet Blaster. Don't try 100 Fire extinguishers. the mass gets bigger.
Actually what's interesting is that as you go up out of earth's gravity, the force of it actually lessens. So not only does the weight of the fuel change by the amount used, it also changes by the height of the rocket itself.
the flyboard air from zapata is the next big thing and i believe soon zapata soon will be demonstrating a working flying bike
Finally understood the throttling down when spacex's rockets reach Max Q
No, the (dot) is part of the variable. m(dot) is just a way of notating the change in mass. It could also be written (delta)m.
for those who thought f=m.v when he was talking about the rocket, the v here is the final velocity of the particles, their initial velocity was zero, so the particles are accelerated from 0 to v almost instantly(say about 1 sec at the most, but actually it would be lesser) so f=m(v-0)/t= m.(v)/1=m.v .
That is a good point but I heard an explanation some thing like higher altitude equals higher gravitational pull so it would require more force from the rocket to take off and gain speed. I don't know if that's right might be just because they don't like the cold weather on top of a mountain...
YES! I had a Toy as a good that was a balloon thing hooked up to water spouts - which you plugged into your garden hose. it was the coolest thing ever! I have often daydreamed about having one again, heh -- and about a human sized one like this. Awesome
2:22 "the balloon represents your harder parts" hehe..okay im done //slapped
it took an 8 minute video to explain something that 12 years of science teachers could not.
This was very cool, I think you did a good job explaining this topic.
One thing you should never do is put your arm, hand, legs or any body part infront of that water stream, you could really hurt yourself. You can even hurt yourself at the self car wash water blaster, imagine how much more powerful this water stream is. Reuse, reduce, recycle. Protect yourself and protect life.
That is correct. However, in instances where the instantaneous change in mass is equivalent to the average change in mass, you could use either m(dot) or (delta)m. I oversimplified a bit, I suppose.
the m they use refers to the change in mass over time.
a is just the change in velocity over time.
so instead of changing the velocity over time, they changed the mass over time. its still force.
3:30 - Even better, the thrust actually slightly increases, because the Isp (specific impulse) will increase as atmospheric pressure decreases, while fuel flow remains roughly constant. Even more g's for the astronauts :-)
I'm a couple years late but anyway, 3:10 the force in the rocket is not 5-8m/s but 15-18m/s, you have to add the gravitation. Also a free falling object has actually a acceleration of 0, not 9.81. It's only realtive to an observer 9.81, in truth, not the falling object is accelerated, but rather the observer standing on the ground is accelerated upwards. This is the concept of relativity and matters especially in the context of g-forces exerted on human bodies.
When you are dealing with things on Earth, the difference between Newtonian gravity and relativistic gravity is semantics. There is no real useful difference. You are also conflating acceleration and force. The 5-8 m/s² is indeed the acceleration. You don't add the acceleration of Earth. You would for the purposes of G-Force, like you said, but again - you don't have to apply General Relativity to compute G-Force.
About the trust of the jet pack...
I think that the majority of the trust does not come from the water passing through the curve that redirects the water from going up to going down.
If the water would be fed in from the top of the unit, you would probably still be lifted out of the water.
So I think there is something else that provides the trust.
My guess is that the water is accellerated because the the nozzle has a smaller diameter than the main tube.
The acceleration exerts a force on the unit according to f=m*a and that's the main force that lifts you out of the water...
Ouch! Glad your teeth survived the run-in with the jet ski--I cringed hard watching that. Thank you for these awesome videos.
Am I the only person who tries to remember each and every lesson on each of his videos, so if somebody asked me one of the questions I'd seem smart?
0:46 remove some excess divergent shape nozzle so that you could accelerate enough. That long divergent exhaust nozzle i'snt design for acceleration.
The principle is simple enough: "Push stuff one way so that you go the other way." The difficulty is the engineering--making it work in a controllable manner.
Please make a video about random numbers. You could include ERNIE the first true random number. And you could explain the differnce between true random and pheurandom numbers.
Don’t Rockets also go faster the higher they are because of less air resistance due to decreased air density so that also explains the exponential curve
Also because they are lighter - since they are getting rid of all that fuel.
I see where you are coming from, and I understand your confusion; I was a bit thrown for a second at first as well. What he actually wrote was F = (m dot) times v , where m dot stands for rate of mass expulsion (kg/s) rather than just plain old m, which stands for mass (kg). With m dot, the units work out, because force in Newtons is (kg m/s^2) and m dot times v is (kg/s) times (m/s), so you end up with (kg m/s^2). :)
High School teachers need to take lessons on how to explain things like this!!!
F=mv? You must be a genius!
Finally an explanation that makes sense! I got all of it- Great Video
Rocket science is really, really simple. The difficult part is rocket engineering. Trying to get an appreciably sized payload to orbit or wherever else without running out of fuel is the tough part.
very neat stuff, but i wish the physics was correct. In the beginning, F=ma, not F=mv.
When talking about the space shuttle reaching orbit the comment, which is something like "most of the acceleration in orbit is horizontal", is incorrect. As it reaches orbit, its velocity becomes constant and all the acceleration is towards the center of the earth...as it FALLS around the Earth. No real biggy unless little Billy is using this for a physics report. Still a fun vid and nicely produced, etc.