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I loved the video and it helped me so much. I do want to clarify that just because the net Force is 0 doesnt mean the object is stationary (as you assumed in Part B of the question), that just means there is no acceleration but there could still be a constant velocity.
A hot air balloon has a volume of 2.50 · 103 m3. The total mass of balloon holster, basket and load are 450 kg. The hot air inside the balloon has density 0.920 kg / m3. The air around the balloon has a density of 1.20 kg / m3. The balloon is attached to the ground with a string. a) Calculate the mass of the hot air in the balloon. b) Calculate the buoyancy on the balloon. The balloon is released from the connection with the ground, after which the balloon starts movement. c) Calculate the acceleration of the balloon just after take-off. Due to the air resistance, the speed of the balloon during the ascent becomes one time constant. The magnitude of the air resistance is given by: F_w = k v ^ 2, where 325 kg / m, and v is the speed of the balloon. d) Calculate the constant speed of the balloon.
I think the question he was answering is only the upward force of the surrounding air. The density of helium is only important once we calculate the counteracting forces. Even if it was filled with normal air the buoyant force would be the same, just countered by the weight of air.
Where is the buoyancy of Helium ? Why you didn't consider the density of Helium? Actually I'm studying about buoyancy of Helium so I'm full of curiosity now. Please let me know~ I just wanna know the reason.
Candy Bear Your question does not make much sense to me atleast. Technicalky, helium does not have a buoyancy, but rather a buiyancy force acting on it. In respect to air, the force is the answer to part A, as we saw him calculate. He did consider thr density of helium while calculating that as far as I see..?
I know what yoyre asking since the number he used to calculate the answer to part A was the density of air and I was curious as to why he didnt use the density of hellium as well.
This seems like it would be a lot easier to come close by just doing an experiment using a finite amount of (He) Helium to reduce the (Fe) until the balloon begins to float - obviously knowing the mass of all the other parts involved as well ----- I was able to make balloons hover in a room using paper matchstick books with normal 'party' balloons ----- the balloons eventually emptied so I was thinking of a sealed bottle of a very light material giving far less leakage 🙂
8:00 15,000 kg is the gross-weight (mass) that the 14,000 cubic meter Helium-balloon could suspended mid-air. Thus 15 tons-force, must be its buoyant-force too, because that is the amount of weight it holds up !!!! Wouldn't you say??? That is just over 1 kg for every cubic-meter of Helium-gas. If the same balloon were filled with H2-Gas, it could likely lift a total of 17 tons-gross-weight (i.e.: 2 tons more than the above helium-balloon)!!!
I don't know if this is what you meant, but helium goes up, because it's lighter that air, so yes. Perhaps you've seen Magrittes monolith (maybe search on youtube, it's a huge 'block' that levitates and rotates with helium) The way it works, is it has a light material and is filled with helium in different parts of its body. It also has nozzles on each side to push it around -> makes it move in the room. It rotates with helium being pushed inside the block to different ends. So if you want it to tip on its side, yoy make the helium inside it go to the corner you want facing up, get it? It's quite cool, and with the right calculations, you could make a simple one yourself: Fill a light box, that holds gasses, with helium so that it levitates at a certain air pressure. For example on shoulder height. The problem with it not having nozzles outside, is that it can easily rise, because it cannot resist the upward force. Still pretty neat, I'm turning just 18 in a couple months but when I have kids someday, I'll definitely show them some Star Wars Jedi stuff with a levitating box like that ;)
From the volume of the air balloon, where volume=mass/density. The volume is then equal to the volume of the Balloon which is roughly equivalent to a sphere, 4/3 *pi*r^3
In the same problem if i add another part like- if initial temp of air inside is 15 degree celcius, and treat it to be ideal gas, now to what temp the balloon should be heated so as to lift the iron block (no other data is given), please help me with this,im stuck at simlilar kind of problem.
I am working on a similar problem that involves a balloon in water with a mass attached to a string. I am wondering if I should include the tension in the string? Why wasnt it considered here?
In that case the mass and the balloon are stated below they don't move! So there will be a tension in that string.. But in this case balloon and the iron are not fixed at anywhere. So they move upward with same acceleration. If we drop two balls which were connected with a string.. The tension in the string will be zero.. Because they are moving with same acceleration. If two objects move with same acceleration there's no force act between them.
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I loved the video and it helped me so much. I do want to clarify that just because the net Force is 0 doesnt mean the object is stationary (as you assumed in Part B of the question), that just means there is no acceleration but there could still be a constant velocity.
I love physics ❤ first and last love in my life ❣️
You are amazing. These are so much more helpful than the textbook. Thank you!
Great lesson on designing my junior model airship.
Be blessed
It would be very helpful if the units were included in the calculations!!!!
Long life my teacher keep up
You deserve more views :(
Ayy another great vid as always!
thanks alot for making these videos, theyve helped me trough soo much
Thank you
Nice work friend
thank you so much !
A hot air balloon has a volume of 2.50 · 103 m3. The total mass of
balloon holster, basket and load are 450 kg. The hot air inside the balloon has
density 0.920 kg / m3. The air around the balloon has a density of 1.20 kg / m3.
The balloon is attached to the ground with a string.
a) Calculate the mass of the hot air in the balloon.
b) Calculate the buoyancy on the balloon.
The balloon is released from the connection with the ground, after which the balloon starts
movement.
c) Calculate the acceleration of the balloon just after take-off.
Due to the air resistance, the speed of the balloon during the ascent becomes one
time constant.
The magnitude of the air resistance is given by:
F_w = k v ^ 2, where 325 kg / m, and v is the speed of the balloon.
d) Calculate the constant speed of the balloon.
How to find the acceleration of the balloon ascending in the air in this case
why did you use the density of air for part a and not the density of helium?
I think the question he was answering is only the upward force of the surrounding air. The density of helium is only important once we calculate the counteracting forces. Even if it was filled with normal air the buoyant force would be the same, just countered by the weight of air.
love you
Where is the buoyancy of Helium ? Why you didn't consider the density of Helium?
Actually I'm studying about buoyancy of Helium so I'm full of curiosity now.
Please let me know~ I just wanna know the reason.
Candy Bear Your question does not make much sense to me atleast. Technicalky, helium does not have a buoyancy, but rather a buiyancy force acting on it. In respect to air, the force is the answer to part A, as we saw him calculate. He did consider thr density of helium while calculating that as far as I see..?
@@tomatrix7525 sorry but exactly where did he consider the density of Helium with respect Air?
I know what yoyre asking since the number he used to calculate the answer to part A was the density of air and I was curious as to why he didnt use the density of hellium as well.
@@flordeluzquintanillacastro6137 me too
This seems like it would be a lot easier to come close by just doing an experiment using a finite amount of (He) Helium to reduce the (Fe) until the balloon begins to float - obviously knowing the mass of all the other parts involved as well ----- I was able to make balloons hover in a room using paper matchstick books with normal 'party' balloons ----- the balloons eventually emptied so I was thinking of a sealed bottle of a very light material giving far less leakage 🙂
thank u sir........💐
Why the volume of the iron does not include in the volume of the air displaced? Pls help mehhh
you are correct and you have to minus the weight of the helium and Ignore the 9.8
is density of air not 1.225?
8:00 15,000 kg is the gross-weight (mass) that the 14,000 cubic meter Helium-balloon could suspended mid-air. Thus 15 tons-force, must be its buoyant-force too, because that is the amount of weight it holds up !!!! Wouldn't you say??? That is just over 1 kg for every cubic-meter of Helium-gas. If the same balloon were filled with H2-Gas, it could likely lift a total of 17 tons-gross-weight (i.e.: 2 tons more than the above helium-balloon)!!!
Where does the upward force ultimately come from? It must be from the differential pressure along the vertical dimension of the balloon, correct?
I don't know if this is what you meant, but helium goes up, because it's lighter that air, so yes.
Perhaps you've seen Magrittes monolith (maybe search on youtube, it's a huge 'block' that levitates and rotates with helium) The way it works, is it has a light material and is filled with helium in different parts of its body. It also has nozzles on each side to push it around -> makes it move in the room. It rotates with helium being pushed inside the block to different ends. So if you want it to tip on its side, yoy make the helium inside it go to the corner you want facing up, get it?
It's quite cool, and with the right calculations, you could make a simple one yourself: Fill a light box, that holds gasses, with helium so that it levitates at a certain air pressure. For example on shoulder height. The problem with it not having nozzles outside, is that it can easily rise, because it cannot resist the upward force.
Still pretty neat, I'm turning just 18 in a couple months but when I have kids someday, I'll definitely show them some Star Wars Jedi stuff with a levitating box like that ;)
How do you find radius if you have only density of air, density of helium in balloon and mass of ballon without air.
From the volume of the air balloon, where volume=mass/density. The volume is then equal to the volume of the Balloon which is roughly equivalent to a sphere, 4/3 *pi*r^3
pog video
thanks but what if we will change "He" to "H2"? how it will change?
In the same problem if i add another part like- if initial temp of air inside is 15 degree celcius, and treat it to be ideal gas, now to what temp the balloon should be heated so as to lift the iron block (no other data is given), please help me with this,im stuck at simlilar kind of problem.
I am working on a similar problem that involves a balloon in water with a mass attached to a string. I am wondering if I should include the tension in the string? Why wasnt it considered here?
In that case the mass and the balloon are stated below they don't move! So there will be a tension in that string.. But in this case balloon and the iron are not fixed at anywhere. So they move upward with same acceleration. If we drop two balls which were connected with a string.. The tension in the string will be zero.. Because they are moving with same acceleration. If two objects move with same acceleration there's no force act between them.
You sound like Scare Theater.
I hate physics
youre gay
Mee too
thank you