Physics 3.5.4b - Projectile Practice Problem 2

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  • Опубликовано: 5 сен 2024
  • Practice Problem on Projectile Motion.

Комментарии • 98

  • @FachrinabilPF
    @FachrinabilPF 9 лет назад +17

    based on your all videos about projectile motion. I realised that you put either vertical/horizontal first on your working is because it depends on the time. If there is a time in the question, you would firstly use horizontal, vice versa.

  • @omersohail95
    @omersohail95 11 лет назад +3

    If it wasn't for your videos, I would've never grasped the whole idea about projectile motion. You don't know how much help your videos have been to me! I am highly in debt and grateful! Thank You So much and Keep up the Enlightenment!

  • @derekowens
    @derekowens  13 лет назад +3

    @DeanNickChase If you look closely you can see in the diagram that it is a stick horse, ridden by a stick figure. Stick horses (and stick figures) are two-dimensional, so they are very thin and extremely lightweight. This gives the horse a tremendous power-to-weight ratio, allowing him to make the jump that a big fat three-dimensional horse could not make.

  • @lindseyhughes
    @lindseyhughes 13 лет назад +4

    thank you so much for this! it's so confusing when my teacher does it but you explain it so well!

  • @KenKaneki-oy3kb
    @KenKaneki-oy3kb 7 лет назад +7

    i love that drawing skills :D

  • @leticiaaguirre8126
    @leticiaaguirre8126 2 года назад

    you're doing my professor's job for him. thank you

  • @babblingmonster1802
    @babblingmonster1802 13 лет назад +1

    Its really saddening to see the view count of such a magnificent video...

  • @RobbyBoy167
    @RobbyBoy167 7 лет назад +5

    100m??!!!! I need to get me that horsey!!!

  • @felixtira5245
    @felixtira5245 10 лет назад +4

    Best video out there!

  • @michaelkraemerman2009
    @michaelkraemerman2009 10 лет назад

    Your videos are incredible. You sir are a miracle worker. thank you very much

  • @mico9423
    @mico9423 8 лет назад

    YOUR GREAT , IF U ARE MY PHYSICS TEACHER SWEAR TO GOD I PASSED WITH HONOR

  • @derekowens
    @derekowens  13 лет назад

    @H2daH acceleration is zero horizontally. This is always the case for projectiles because gravity always pulls down, and never exerts any force horizontally.

  • @jensons88
    @jensons88 13 лет назад

    the lesson here is clear. on my channel is a projectile motion demo that you can watch. it's actually a program that you can download from softpedia

  • @catherinsucalit975
    @catherinsucalit975 9 лет назад

    Thanks a bunch its been long years since I was in physics

  • @mikemai8568
    @mikemai8568 9 лет назад +1

    Great video, Derek. Thank you for breaking them down in steps.

  • @little0range
    @little0range 11 лет назад

    ur drawings make physics much more enjoyable :)

  • @gr33nplastic
    @gr33nplastic 13 лет назад

    @derekowens as the previously mentioned teacher from TheJezza2, must say that I respect your work and clear explanations. I have commonly referenced your videos in my physics class for at home help. Keep doing the good "f x d x Cos(theta)"!

  • @derekowens
    @derekowens  13 лет назад

    @getrichquickideas Thinking from the start to the peak, which is only half of the flight, gives you a result of 2.5 seconds. This is half the total time, so the total time is five seconds.

  • @tutstorial8474
    @tutstorial8474 4 года назад +1

    well here's another approach:
    let T = total time (start to peak, peak to...)
    T = 5s.
    R = 100m.
    ¢ = angle
    since T = 2Voy/g
    T = 2Vosin(¢)/g
    Vo = gT/2sin(¢) --------- eq1.
    Vo = (9.81)(5)/2sin(¢)
    x = Voxt ---------------------- eq2
    100 = Vocos(¢)(5)
    Vo = 100/5cos(¢)
    equate e1 & eq 2
    9.81(5)/2sin(¢) = 100/(5cos(¢))
    sin(¢)/cos(¢) = 5(5)(9.81)/2(100)
    tan(¢) = {(5)(5)(9.81)/2(100)}
    ¢ = 50.81°
    substituting ¢ to either eq1 or eq.2
    Vo = 31.6 m/s

    • @Haza-rp1cb
      @Haza-rp1cb 3 года назад

      U did all that for no reply

    • @tutstorial8474
      @tutstorial8474 3 года назад

      well, u replied
      thank you

    • @bloodisfuel9882
      @bloodisfuel9882 7 месяцев назад

      wow! I am very impressed by your work. well done

  • @bloodisfuel9882
    @bloodisfuel9882 7 месяцев назад

    hey there, I really appreciate your video. but at 3:25 I did not really understand much. Why would you make the time 2.5s? I know that at 2.5s that's when farmer bob and his horse reached maximum height, but why would you do that? Is there another way to get the initial vertical velocity here? thanks

  • @koalakid3609
    @koalakid3609 Год назад

    This is intresting. VERY.

  • @IrisVollmer
    @IrisVollmer 13 лет назад

    Ahhhh yeeeah! Bring it on exam 1. Thanks so much mista! :)

  • @remargonzaga3426
    @remargonzaga3426 Год назад

    i'm sorry. but, shouldn't be the initial velocity for x Vocos(theta)? thus, Vo=100m/(5s cos(theta))?

  • @DannyDoomPink
    @DannyDoomPink 13 лет назад

    Thanks for these amazing videos, now when i solve a problem i can actually say that i understand whats going on haha

  • @DaTurdburglar
    @DaTurdburglar 13 лет назад +1

    Thanks for the vids! They really helped me alot. :D

  • @xPinoyTribal
    @xPinoyTribal 8 лет назад

    what is the reason we should assume that there is no horizontal acceleration? WHat if you jump from a stop? there would be both horizontal and veritcal acceleration

    • @derekowens
      @derekowens  8 лет назад +1

      +xPinoyTribal Right, I see what you are saying. While you are jumping, pushing with your legs, there is definitely horizontal as well as vertical acceleration. Once you are airborne, however, coasting and out of contact with the ground, then at that point you are properly considered a projectile, and the only acceleration is the downward acceleration of gravity (assuming that we ignore air resistance).

    • @exogendesign4582
      @exogendesign4582 8 лет назад

      +xPinoyTribal pre hehe, kaya walang horinzontal ang acceleration, kasi unbalance ang force sa x-direction(horizontal) dahil narin sa air resistance,
      may ang acceleration sa Y vertical acceleration dahil constant at uniform ang force, at ang tawag don gravitational force 9.81m/s so dahil nag rereact lang ang gravity sa vertical , ang Y lang may acceleration kasi nag babago ang acceleration dpende sa time at distance, habang constant palagi ang horizontal, gets mo po ?> hehehe

  • @TheJezza2
    @TheJezza2 13 лет назад

    Whats up Mr.Butler's class!!!

  • @derekowens
    @derekowens  13 лет назад

    @jkoscak I prefer m/s, although m s^-1 is mathematically equivalent, and can fit neatly on one line when typing. I think the algebra is more clear, though, with it written as a fraction.

  • @mickyadams8502
    @mickyadams8502 11 лет назад

    why dont you use 1/2 as often found in the formula 1/2at squared. When you calculate V zero

  • @user-wb1ko5uc4m
    @user-wb1ko5uc4m 6 месяцев назад

    Well done

  • @kennysundiam
    @kennysundiam 14 лет назад

    thank you very much sir!.keep it up :D you are a much better than my prof.haha

  • @goshiluvarchie
    @goshiluvarchie 11 лет назад

    Your videos are incredibly helpful! Thanks. :-)

  • @mercydelani7943
    @mercydelani7943 11 лет назад

    to find the initial velocity..can i use the parrelogram law/triangle law insead of pythogorus theorem

  • @Gsmstfreshie
    @Gsmstfreshie 13 лет назад

    what if it asks for the landing velocity? would that just be the horizontal velocity, which is 20m/s?
    please answer my question, thank you!

  • @kinstlerh97
    @kinstlerh97 11 лет назад

    wow, great job explaining! very helpful

  • @MisterBazarao
    @MisterBazarao 12 лет назад

    Isnt it easier to use U for initial velocity instead of V zero?

  • @getrichquickideas
    @getrichquickideas 13 лет назад

    Why is the time for horizontal (5sec) different from you time for the verticle (2.5 sec) ?

  • @lauratwilight1
    @lauratwilight1 13 лет назад

    This guy's drawing is awesome

  • @irwinisraeltomas7097
    @irwinisraeltomas7097 8 лет назад +1

    ok thanks derek for this video.

  • @smileinc
    @smileinc 13 лет назад

    Doesn't tan^-1(24.5/20)= 56.4 degrees?

  • @tncreations1267
    @tncreations1267 Год назад

    thank you very much.

  • @himorthem5406
    @himorthem5406 Год назад

    It works. Thank you

  • @EdwardCullensMayo
    @EdwardCullensMayo 12 лет назад

    these videos are fucking awesome!! i'm gonna go ham on my test on monday!!

  • @Rittiuu
    @Rittiuu Месяц назад

    Because v zero is from theta angle so vx will v cos thata I think you made mistake

  • @Yann1
    @Yann1 8 лет назад

    your such a good teacher derek :D

  • @H2daH
    @H2daH 13 лет назад

    why is (a)=0 ?
    in the first horizontal eqaution

  • @katehsu3642
    @katehsu3642 3 года назад

    Thank you 🙏

  • @webjeff2002
    @webjeff2002 14 лет назад

    @emiri, thank you.

  • @boss2dawerld750
    @boss2dawerld750 3 года назад

    i didn’t consider the “start from peak” part for the vertical component solving, but i still got 24.5 seconds as the answer,,, is that alright?? THANK YOUU

    • @boss2dawerld750
      @boss2dawerld750 3 года назад +1

      oh wow didn’t notice this video was posted 11 years ago already oh wow

    • @derekowens
      @derekowens  3 года назад +1

      Yes, there are other ways to solve it. You can consider the motion from start to finish, and as long you use the correct initial and final velocity you should get the same answer for the time.

    • @derekowens
      @derekowens  3 года назад +3

      @@boss2dawerld750 11 years, and I'm still here! Lots to be thankful for.

    • @adnankamal3697
      @adnankamal3697 Год назад

      @@derekowens since the flight time is 5 sec which means at t equal 5 they reached the ground doesn't that mean that at t equal 5 the vertical velocity equal 0?

    • @derekowens
      @derekowens  Год назад +1

      @@adnankamal3697 t=5s is the end of the flight, so the velocity at t=5s is the impact velocity. Think of the final velocity as being the speed with which it hits.

  • @funfofacts
    @funfofacts 10 месяцев назад

    im here 14 years later

    • @derekowens
      @derekowens  10 месяцев назад

      And I'm still here, too!

  • @monkieful
    @monkieful 12 лет назад

    Bravo this video is very good keep up the good work.

  • @albertcao96
    @albertcao96 11 лет назад

    Dude, you are the best

  • @MarMONEY-wz4zl
    @MarMONEY-wz4zl Год назад

    Can you lmk where the 9.8m2 come from

    • @derekowens
      @derekowens  Год назад

      9.8 m/s^2 is the acceleration due to gravity. At least that's the value near earth's surface. And since a lot of physics problems take place near earth's surface, that value shows up fairly often, so it's a good number to know for basic physics work.

  • @emmanuelmaluba9653
    @emmanuelmaluba9653 3 года назад

    This is awesome

  • @rubiksmaster301
    @rubiksmaster301 5 лет назад

    The only reason I'm watching this is because it's a physics homework assignment.

  • @babakmahour
    @babakmahour 12 лет назад

    u got me!!!! good one thx

  • @tahasilat7394
    @tahasilat7394 6 лет назад

    what software do you use?

  • @NatashaKN
    @NatashaKN Год назад +2

    I'm watching this video in 2023

  • @jkoscak
    @jkoscak 13 лет назад

    m/s or ms-1 ? what do you like better? :p

  • @emmamercado9066
    @emmamercado9066 5 лет назад

    Thank you so much

  • @malaklove464
    @malaklove464 10 лет назад

    thank you so much

  • @hardcore2103
    @hardcore2103 8 лет назад

    where did 9.8 m/s come from??

  • @anajo240
    @anajo240 8 лет назад

    Would you explain why in vertical initial velocity, v=0? Great video. Thanks

    • @Nuns341
      @Nuns341 5 лет назад

      this is probably too late but here lol when a object travels in a parabolic path, there comes a time ,right before when the object starts going down, the object only has horizontal force acting on it as the vertical force in that very instance is zero(the object goes up and when its done going up, in that very moment the final velocity is 0), and since its a parabola that means it took 2.5 seconds to go up and 2.5 to go down

  • @bohemian3.5
    @bohemian3.5 6 лет назад

    When your doing the vertical motion, why is time 2.5 seconds? Please answer...

    • @DangerFishing
      @DangerFishing 6 лет назад

      Thats half of the time so the velocity in the y direction is changing from up to down which makes the velocity in the y-direction 0, which enables you to plug the numbers in to solve for the inital velocity of y.

  • @webjeff2002
    @webjeff2002 14 лет назад

    How did you get the number 9.8 m/^2?

  • @irwinisraeltomas7097
    @irwinisraeltomas7097 8 лет назад

    is the peak half of the total time?

    • @derekowens
      @derekowens  8 лет назад +1

      +irwin israel Tomas Yes, but only if it starts and ends at the same height.

  • @abridgetool
    @abridgetool 3 года назад

    The problem is quite old.
    So the video is.

  • @uchwuzhere
    @uchwuzhere 10 лет назад

    Can someone explain to me why he used inverse tangent?

    • @zebunnisachughtai
      @zebunnisachughtai 10 лет назад

      Tangent theta is the ratio of opposite over adjacent but we don't want tan theta we want theta so when we take tan to the other side of the equation we get tan inverse theta (oppo/adj). I hope that was helpful :)

    • @catherinsucalit975
      @catherinsucalit975 9 лет назад

      Use the inverse tangent to determine angle in degrees and seconds

    • @uchwuzhere
      @uchwuzhere 9 лет назад

      Oh, I took this class in the summer, but thanks anyways guys.

  • @vj692
    @vj692 7 лет назад

    great

  • @takumikanna5805
    @takumikanna5805 9 лет назад

    thank you!!!!!

  • @heavenz94
    @heavenz94 11 лет назад

    thnks

  • @miguellserrano3312
    @miguellserrano3312 2 года назад

    yo, i can see u r a good drawer haha

  • @smileinc
    @smileinc 13 лет назад

    @smileinc oh nevermind, my calculator needed reseting. :(

  • @ggxsky4811
    @ggxsky4811 Год назад

    Easy

  • @username6333
    @username6333 12 лет назад

    Laughing at the reply to the horse comment.

  • @j.jcagney6522
    @j.jcagney6522 9 лет назад

    Thank you so much.