Physics 3.5.4b - Projectile Practice Problem 2

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  • เผยแพร่เมื่อ 25 ต.ค. 2009
  • Practice Problem on Projectile Motion.

ความคิดเห็น • 97

  • @omersohail95
    @omersohail95 11 ปีที่แล้ว +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!

  • @FachrinabilPF
    @FachrinabilPF 9 ปีที่แล้ว +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.

  • @lindseyhughes
    @lindseyhughes 12 ปีที่แล้ว +4

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

  • @michaelkraemerman2009
    @michaelkraemerman2009 9 ปีที่แล้ว

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

  • @derekowens
    @derekowens  13 ปีที่แล้ว +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.

  • @leticiaaguirre8126
    @leticiaaguirre8126 2 ปีที่แล้ว

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

  • @gr33nplastic
    @gr33nplastic 13 ปีที่แล้ว

    @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)"!

  • @KenKaneki-oy3kb
    @KenKaneki-oy3kb 7 ปีที่แล้ว +7

    i love that drawing skills :D

  • @catherinsucalit975
    @catherinsucalit975 9 ปีที่แล้ว

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

  • @felixtira5245
    @felixtira5245 10 ปีที่แล้ว +4

    Best video out there!

  • @little0range
    @little0range 11 ปีที่แล้ว

    ur drawings make physics much more enjoyable :)

  • @goshiluvarchie
    @goshiluvarchie 11 ปีที่แล้ว

    Your videos are incredibly helpful! Thanks. :-)

  • @RobbyBoy167
    @RobbyBoy167 7 ปีที่แล้ว +5

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

  • @mikemai8568
    @mikemai8568 8 ปีที่แล้ว +1

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

  • @IrisVollmer
    @IrisVollmer 13 ปีที่แล้ว

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

  • @DaTurdburglar
    @DaTurdburglar 13 ปีที่แล้ว +1

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

  • @mico9423
    @mico9423 8 ปีที่แล้ว

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

  • @babblingmonster1802
    @babblingmonster1802 13 ปีที่แล้ว +1

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

  • @DannyDoomPink
    @DannyDoomPink 12 ปีที่แล้ว

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

  • @derekowens
    @derekowens  13 ปีที่แล้ว

    @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.

  • @derekowens
    @derekowens  13 ปีที่แล้ว

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

  • @kinstlerh97
    @kinstlerh97 10 ปีที่แล้ว

    wow, great job explaining! very helpful

  • @Yann1
    @Yann1 8 ปีที่แล้ว

    your such a good teacher derek :D

  • @irwinisraeltomas7097
    @irwinisraeltomas7097 8 ปีที่แล้ว +1

    ok thanks derek for this video.

  • @kennysundiam
    @kennysundiam 13 ปีที่แล้ว

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

  • @himorthem5406
    @himorthem5406 ปีที่แล้ว

    It works. Thank you

  • @tncreations1267
    @tncreations1267 10 หลายเดือนก่อน

    thank you very much.

  • @koalakid3609
    @koalakid3609 ปีที่แล้ว

    This is intresting. VERY.

  • @albertcao96
    @albertcao96 11 ปีที่แล้ว

    Dude, you are the best

  • @babakmahour
    @babakmahour 12 ปีที่แล้ว

    u got me!!!! good one thx

  • @mercydelani7943
    @mercydelani7943 11 ปีที่แล้ว

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

  • @bloodisfuel9882
    @bloodisfuel9882 5 หลายเดือนก่อน

    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

  • @derekowens
    @derekowens  12 ปีที่แล้ว

    @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.

  • @EdwardCullensMayo
    @EdwardCullensMayo 12 ปีที่แล้ว

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

  • @j.jcagney6522
    @j.jcagney6522 9 ปีที่แล้ว

    Thank you so much.

  • @lauratwilight1
    @lauratwilight1 13 ปีที่แล้ว

    This guy's drawing is awesome

  • @emmanuelmaluba9653
    @emmanuelmaluba9653 3 ปีที่แล้ว

    This is awesome

  • @Gsmstfreshie
    @Gsmstfreshie 13 ปีที่แล้ว

    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!

  • @webjeff2002
    @webjeff2002 14 ปีที่แล้ว

    @emiri, thank you.

  • @MisterBazarao
    @MisterBazarao 12 ปีที่แล้ว

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

  • @katehsu3642
    @katehsu3642 3 ปีที่แล้ว

    Thank you 🙏

  • @malaklove464
    @malaklove464 9 ปีที่แล้ว

    thank you so much

  • @getrichquickideas
    @getrichquickideas 13 ปีที่แล้ว

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

  • @remargonzaga3426
    @remargonzaga3426 ปีที่แล้ว

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

  • @takumikanna5805
    @takumikanna5805 8 ปีที่แล้ว

    thank you!!!!!

  • @gogolscience9159
    @gogolscience9159 8 หลายเดือนก่อน

    im here 14 years later

    • @derekowens
      @derekowens  8 หลายเดือนก่อน

      And I'm still here, too!

  • @user-wb1ko5uc4m
    @user-wb1ko5uc4m 4 หลายเดือนก่อน

    Well done

  • @xPinoyTribal
    @xPinoyTribal 8 ปีที่แล้ว

    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 ปีที่แล้ว +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 ปีที่แล้ว

      +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

  • @emmamercado9066
    @emmamercado9066 5 ปีที่แล้ว

    Thank you so much

  • @jensons88
    @jensons88 12 ปีที่แล้ว

    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

  • @TheJezza2
    @TheJezza2 13 ปีที่แล้ว

    Whats up Mr.Butler's class!!!

  • @tahasilat7394
    @tahasilat7394 6 ปีที่แล้ว

    what software do you use?

  • @mickyadams8502
    @mickyadams8502 11 ปีที่แล้ว

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

  • @H2daH
    @H2daH 13 ปีที่แล้ว

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

  • @rubiksmaster301
    @rubiksmaster301 5 ปีที่แล้ว

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

  • @smileinc
    @smileinc 12 ปีที่แล้ว

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

  • @jkoscak
    @jkoscak 12 ปีที่แล้ว

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

  • @vj692
    @vj692 7 ปีที่แล้ว

    great

  • @MarMONEY-wz4zl
    @MarMONEY-wz4zl 10 หลายเดือนก่อน

    Can you lmk where the 9.8m2 come from

    • @derekowens
      @derekowens  10 หลายเดือนก่อน

      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.

  • @boss2dawerld750
    @boss2dawerld750 3 ปีที่แล้ว

    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 ปีที่แล้ว +1

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

    • @derekowens
      @derekowens  3 ปีที่แล้ว +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 ปีที่แล้ว +3

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

    • @adnankamal3697
      @adnankamal3697 ปีที่แล้ว

      @@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  ปีที่แล้ว +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.

  • @monkieful
    @monkieful 12 ปีที่แล้ว

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

  • @anajo240
    @anajo240 7 ปีที่แล้ว

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

    • @Nuns341
      @Nuns341 5 ปีที่แล้ว

      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

  • @hardcore2103
    @hardcore2103 7 ปีที่แล้ว

    where did 9.8 m/s come from??

    • @perrycheng4876
      @perrycheng4876 7 ปีที่แล้ว

      vertical acceleration from gravity

  • @webjeff2002
    @webjeff2002 14 ปีที่แล้ว

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

  • @miguellserrano3312
    @miguellserrano3312 2 ปีที่แล้ว

    yo, i can see u r a good drawer haha

  • @smileinc
    @smileinc 12 ปีที่แล้ว

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

  • @irwinisraeltomas7097
    @irwinisraeltomas7097 8 ปีที่แล้ว

    is the peak half of the total time?

    • @derekowens
      @derekowens  8 ปีที่แล้ว +1

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

  • @abridgetool
    @abridgetool 3 ปีที่แล้ว

    The problem is quite old.
    So the video is.

  • @uchwuzhere
    @uchwuzhere 10 ปีที่แล้ว

    Can someone explain to me why he used inverse tangent?

    • @zebunnisachughtai
      @zebunnisachughtai 10 ปีที่แล้ว

      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 ปีที่แล้ว

      Use the inverse tangent to determine angle in degrees and seconds

    • @uchwuzhere
      @uchwuzhere 9 ปีที่แล้ว

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

  • @heavenz94
    @heavenz94 11 ปีที่แล้ว

    thnks

  • @NatashaKN
    @NatashaKN ปีที่แล้ว +2

    I'm watching this video in 2023

  • @sizwemaseko5223
    @sizwemaseko5223 6 ปีที่แล้ว

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

    • @DangerFishing
      @DangerFishing 5 ปีที่แล้ว

      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.

  • @tutstorial8474
    @tutstorial8474 4 ปีที่แล้ว +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 ปีที่แล้ว

      U did all that for no reply

    • @tutstorial8474
      @tutstorial8474 3 ปีที่แล้ว

      well, u replied
      thank you

    • @bloodisfuel9882
      @bloodisfuel9882 5 หลายเดือนก่อน

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

  • @username6333
    @username6333 12 ปีที่แล้ว

    Laughing at the reply to the horse comment.

  • @ggxsky4811
    @ggxsky4811 ปีที่แล้ว

    Easy