Horizontally launched projectile | Two-dimensional motion | Physics | Khan Academy

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  • เผยแพร่เมื่อ 1 ก.พ. 2025

ความคิดเห็น • 291

  • @ericaritchie9136
    @ericaritchie9136 7 ปีที่แล้ว +221

    I am such a visual learner and I do online school so it's hard for me to teach myself some things especially in physics. This really helped me, i appreciate it.

    • @oneagainsthumanity7893
      @oneagainsthumanity7893 4 ปีที่แล้ว +29

      3 years later and all we have is online school

    • @josephpate7646
      @josephpate7646 4 ปีที่แล้ว +8

      @@oneagainsthumanity7893 this person is probably in college now😪

    • @oneagainsthumanity7893
      @oneagainsthumanity7893 4 ปีที่แล้ว +5

      @@josephpate7646 Damn i never thought about that 🤭😔

  • @xx-gamer-xx9476
    @xx-gamer-xx9476 8 ปีที่แล้ว +122

    i swear i understood everything thing more than the class

  • @fumikotsukumi017
    @fumikotsukumi017 5 ปีที่แล้ว +109

    “They REAAAAALLLY want to plug in 5m/s as the velocity in y; but don’t do it, it’s a trap.”
    I like this dude already

    • @premseelan
      @premseelan 4 ปีที่แล้ว +15

      "People are just *dying* to stick that 5m/s in there..." 😂

  • @delwlr
    @delwlr 6 ปีที่แล้ว +608

    I'm watching this the day before my physics exam lol

    • @cappuccino2901
      @cappuccino2901 5 ปีที่แล้ว +10

      how did u got?

    • @keane6635
      @keane6635 5 ปีที่แล้ว +7

      lmao fuckin same HAHHAHAHHAAH

    • @herrerarafael1914
      @herrerarafael1914 5 ปีที่แล้ว +20

      Im watching this just minutes before final exam

    • @maharajdattumaharaj5360
      @maharajdattumaharaj5360 5 ปีที่แล้ว +6

      I'm watching on the day of exam, I have 2 hrs left for the exam

    • @codyclark7525
      @codyclark7525 4 ปีที่แล้ว +3

      right there with you lol

  • @mimichfury6329
    @mimichfury6329 5 ปีที่แล้ว +57

    U clearly understand students soo damn well mate. My mind is oficially blown by your teaching.. thnk yu mate

  • @stormwolf4488
    @stormwolf4488 6 ปีที่แล้ว +213

    Hopefully the cliff diver doesn't ignore air resistance lol

    • @xanthman7528
      @xanthman7528 4 ปีที่แล้ว +6

      If they do ignore it, then that's pretty impressive.

    • @MathPhysicsEngineering
      @MathPhysicsEngineering 3 ปีที่แล้ว +1

      To those are intrested in an in-depth analysis of the physics and the gometry of teh projectile motion, with simulation and visualization I recommend:
      th-cam.com/video/HPehCUv6bEY/w-d-xo.html&ab_channel=Math%2CPhysics%2CEngineering

  • @andreasbringemeier3689
    @andreasbringemeier3689 7 ปีที่แล้ว +311

    why arnt my physics teachers this good?

    • @charliephinney9105
      @charliephinney9105 7 ปีที่แล้ว +80

      Looks like your English teachers aren't the best either.

    • @chiraggupta2645
      @chiraggupta2645 7 ปีที่แล้ว +1

      Lol....same

    • @carlenger9707
      @carlenger9707 6 ปีที่แล้ว +5

      Your profile picture makes you look like you're 5. There's literally no way you're in physics.

    • @MsOluyemi
      @MsOluyemi 6 ปีที่แล้ว +7

      Svensk Gamer that could be his son -.-

    • @nadineebada6557
      @nadineebada6557 5 ปีที่แล้ว +2

      @@MsOluyemi or his brother

  • @MegaJefflin
    @MegaJefflin 6 ปีที่แล้ว +45

    This teacher is better than my teacher, finally someone explain this with human language, and also this teacher is fun, dont try this at home lol

  • @rubycannon
    @rubycannon 7 ปีที่แล้ว +33

    Thanks! My physics teacher bores me to sleep and I end up learning some of it on my own time. Wonderful explanation!

  • @jorgezheng5169
    @jorgezheng5169 6 ปีที่แล้ว +18

    Words cannot express how much you have helped me. My gratitude for you is endless.

  • @migueldiax7947
    @migueldiax7947 3 ปีที่แล้ว +8

    I am in AP physics this year and the teacher blew through the first few “recap” lessons, I didn’t take any prior physics class so I’m in a loop lol. Very well explained!

  • @jacobtlg9029
    @jacobtlg9029 2 ปีที่แล้ว +3

    This guy litterally saved my grade. I am a freshman in highschool. Im not very smart but the school still decide to put me in physics. I am so lost all the time. It also doesnt help that my teacher is kind of bad at teaching. I think she might have dementia. REgardless thank you so much for this awesome video you really helped with understanding horizantally launched projectiles.

  • @kaylynn3459
    @kaylynn3459 7 ปีที่แล้ว +6

    Lmao I love this! I’m in the library without headphones, and this so amusing with no sound and the captions on because of the humor. Thanks for the help!

  • @temi7036
    @temi7036 5 ปีที่แล้ว +3

    Thank you so much!! I have a physics test tomorrow on horizontal projectile motion and you explained this really well

  • @Landoscurlyhair
    @Landoscurlyhair 9 หลายเดือนก่อน +1

    Thank you so much for this! 😭 my school doesn't do lectures but instead just give us notes. This topic, they didn't really elaborate about this one and tomorrow is our exam, FINAL EXAM. 😭. Now I understand everything about this now 😭

  • @Unveiiled
    @Unveiiled 8 ปีที่แล้ว +23

    Really helped me, got my a in the exam! :)

  • @boshtua
    @boshtua 7 ปีที่แล้ว +4

    Got a test tomorrow and I have no idea what I'm doing, I'ma watch this and hope it helps

  • @dawitergichofanta7093
    @dawitergichofanta7093 4 ปีที่แล้ว

    The most open person ever. YOU ARE THE BEST, DAVID

  • @davidsscope
    @davidsscope 2 ปีที่แล้ว +1

    I searched "why greater heights provide further distance when jumping into water" because of the movie "Deep Water Horizon" showing Mark Walberg climbing higher up the drilling platform before jumping to clear the fire in the water. Now I know why he did what he did. And your teaching skills are amazing

  • @jaydenandrews8847
    @jaydenandrews8847 6 ปีที่แล้ว +6

    How do you do this if you’re given the range but not the y value

  • @chard0nka
    @chard0nka 6 ปีที่แล้ว +3

    Hey thank you for this video & explanation! Really helped me in reviewing for my physics quiz!

  • @Furzayra02
    @Furzayra02 2 ปีที่แล้ว +1

    Thanks this was very helpful

  • @shanks6190
    @shanks6190 4 ปีที่แล้ว +4

    I'm watching this DURING my physics exam

  • @saraowens8413
    @saraowens8413 2 ปีที่แล้ว +1

    Great video. This just helped so much! I was having such a hard time with this. Thank you!

  • @cmackatlanta
    @cmackatlanta 7 ปีที่แล้ว +2

    How would we determine the angle at which the person hits ground at various distances?

  • @m4lmas
    @m4lmas 7 ปีที่แล้ว +3

    5:25 best teacher ever

    • @malanil1
      @malanil1 6 ปีที่แล้ว +1

      lol

  • @glob567
    @glob567 4 ปีที่แล้ว +2

    thank you so much, this really helped me finally understand this

  • @justinkim4861
    @justinkim4861 7 ปีที่แล้ว +7

    taking the class next year wish me luck!

  • @jean-christopheboucher6306
    @jean-christopheboucher6306 6 ปีที่แล้ว +2

    you save my night! thanks a lot!

  • @toereh7848
    @toereh7848 4 ปีที่แล้ว +3

    I’ve learned more from this than 4 months with my teacher

  • @liquidmo5543
    @liquidmo5543 4 ปีที่แล้ว +2

    Ah yes, no one jump off a cliff at home

  • @TheScienceCube
    @TheScienceCube 5 ปีที่แล้ว

    Even If 20% of the teachers in the world start teaching like this, the world will advance a lot faster!!

  • @jikunue9187
    @jikunue9187 6 ปีที่แล้ว +3

    you should be my physics professor!

  • @jacobpickos733
    @jacobpickos733 ปีที่แล้ว

    I love this. Thank you.

  • @kyandrew7942
    @kyandrew7942 3 ปีที่แล้ว

    learning this 1 hour before our examinations

  • @allanerissat2296
    @allanerissat2296 7 ปีที่แล้ว +3

    Like Bucky Roberts, but in Khan Academy! Great video!

    • @MegaJefflin
      @MegaJefflin 6 ปีที่แล้ว

      lol, exactly, but this one is funner

  • @muneebanjum6268
    @muneebanjum6268 4 ปีที่แล้ว

    BEST EXPLANATION EVER!!!

  • @xwllxi
    @xwllxi หลายเดือนก่อน

    Bro, I watch your videos the day before the exam.

  • @peppervfx
    @peppervfx 3 ปีที่แล้ว

    My teacher accent is kinda hard to understand so helps out a lot. Thank you.

  • @bishaldas6790
    @bishaldas6790 5 ปีที่แล้ว +2

    More efficient than my phy classes

  • @ModjadjiMamaila-cs4ek
    @ModjadjiMamaila-cs4ek ปีที่แล้ว

    U are really a good tutor

  • @tobiiyarou
    @tobiiyarou 3 ปีที่แล้ว

    i genuinely wanna meet this guy

  • @stephanieshen3713
    @stephanieshen3713 5 ปีที่แล้ว +1

    God bless khan academy

  • @alanjacob1488
    @alanjacob1488 ปีที่แล้ว

    Basically use eqns of motion and apply proper sign convention. For other cases too, when projected at an gle theta above and below horizontal

  • @xox102
    @xox102 5 ปีที่แล้ว +1

    How do you find the height of the cliff given the velocity and the the distance it landed?

  • @phendyella9742
    @phendyella9742 2 ปีที่แล้ว

    I finally get it . Thank you

  • @ntokozosikhosana-zj5nr
    @ntokozosikhosana-zj5nr ปีที่แล้ว

    What we solving for how far, are we solving vertically or horizontally?

  • @iron1349
    @iron1349 7 ปีที่แล้ว +1

    This stuff makes a TON more sense when you have a calculator to help with finding square roots

  • @The_Unintelligent_Speculator
    @The_Unintelligent_Speculator 5 ปีที่แล้ว +1

    Yes. I could have been a genius with this sort of tuition. Cheers 🍻

  • @amarlist1
    @amarlist1 ปีที่แล้ว

    the sound effects are great, i like Sal, cuz hes prob like super smart af, but this narrator is great too, 1:45

  • @waffielz3106
    @waffielz3106 7 ปีที่แล้ว +2

    a video not made by khan? praise the sun

  • @ziyadfara4760
    @ziyadfara4760 ปีที่แล้ว

    What a beautiful video. Explained so well. Great teacher.

  • @Yourlocaljp
    @Yourlocaljp 6 ปีที่แล้ว +2

    BASED DAVID!!! Thank you

  • @voyager7971
    @voyager7971 5 ปีที่แล้ว

    Thanks for the refresh!

  • @brianbruno1786
    @brianbruno1786 6 ปีที่แล้ว +1

    Can you do colliding??

  • @bla__berries
    @bla__berries 4 ปีที่แล้ว +6

    Lol. This part of projectile motion always confused me but I love the way it was explained here. I even laughed😂. I do not laugh while learning physics.

  • @alstugvideos
    @alstugvideos ปีที่แล้ว

    This might sound strange but what software are you using?

  • @successparody
    @successparody ปีที่แล้ว

    I found this extremely helpful. I really appreciate what you guys do. Thank you

  • @mixedguy2038
    @mixedguy2038 4 ปีที่แล้ว +1

    I love the way you teach

  • @babarm9815
    @babarm9815 8 ปีที่แล้ว +1

    This has to be the best video ever.

  • @klydeurbiztondo3601
    @klydeurbiztondo3601 6 ปีที่แล้ว +1

    Regarding the value of downward acceleration due to gravity, why did it happen that it is negative? When in fact the object/body is accelerating not decelerating? Can someone explain?

    • @carultch
      @carultch 2 ปีที่แล้ว

      The sign on acceleration has nothing to do with whether the object is speeding up or slowing down. A negative sign on any kinematics quantity just means that it is opposite the direction you arbitrarily define as positive. It is customary to define up as positive, but you don't necessarily need to do this.

  • @maki4568
    @maki4568 6 ปีที่แล้ว +3

    A bullet is fired 30deg to the horizontal with a speed of 200m/s. The acceleration of the bullet is 15 m/s^2 vertically downward
    What is the change in velocity after 2 seconds?

    • @lopamudrakar5680
      @lopamudrakar5680 5 ปีที่แล้ว +1

      Hey! Initial velocity= 200 m/s, final velocity after 2s= 186.81m/s, the change in velocity after 2s is -13.19 m/s.

    • @lt.ifeplumz1315
      @lt.ifeplumz1315 5 ปีที่แล้ว

      Velocity only changes during vertical motion. So, we are neglecting the horizontal motion since the velocity here is always constant.
      During vertical motion,
      Acceleration =Δv/t.
      Initially, during the vertical motion, the initial velocity is usually zero.
      15ms-² = Vf - 0./2s.
      Vf = 15ms-² × 2s.
      Vf = 30ms-¹.
      ΔV = 30 - 0 = 30ms-¹.

  • @lixinz.4708
    @lixinz.4708 6 ปีที่แล้ว +1

    5:25 how is gravity -9.8 if your object is going down and the gravity is constantly facing downward? wouldn't it be positive?

    • @nidhiupadhyay416
      @nidhiupadhyay416 5 ปีที่แล้ว +2

      No, acceleration is a vector quantity and object is falling downward.

  • @rennibae
    @rennibae 9 วันที่ผ่านมา

    Watching this before my Physics Midterm next weeek 😓

  • @BMitts
    @BMitts 4 ปีที่แล้ว

    This literally is more helpful than the videos my teacher makes

  • @alstugvideos
    @alstugvideos ปีที่แล้ว

    Thank you very much for this.

  • @wenymwila5021
    @wenymwila5021 5 ปีที่แล้ว +1

    Physics I see you
    Thank for the video sir

  • @byehikaveh
    @byehikaveh 5 ปีที่แล้ว

    Thank you so much! Im not going to fail my physics test tom

  • @rakiedi8347
    @rakiedi8347 3 ปีที่แล้ว

    Such a good Explanation 👍👏 It helped tnx 😊

  • @uzmajamil105
    @uzmajamil105 6 ปีที่แล้ว +3

    Thank youu

  • @zaneninjago410
    @zaneninjago410 3 ปีที่แล้ว

    this is great thanks!

  • @EllietheEngene
    @EllietheEngene 3 ปีที่แล้ว

    is there a vertical version of this?

  • @keniatorres5598
    @keniatorres5598 6 ปีที่แล้ว +2

    can anyone explain how to do the math portion once he gets to the radical

    • @adilmohammed6897
      @adilmohammed6897 4 ปีที่แล้ว

      hi, so when you take vertical displacement (dy) as + 30 instead of -30, you will find that the value inside the root (that long line, i am assuming that's not what they call in your country) becomes negative. now, the square root of negative numbers come under the family of complex numbers and most calculators aren't build to do that (cos complex numbers are imaginary and unlikely anyone is gonna use irl) hope it helps

  • @jacobgordon6052
    @jacobgordon6052 5 ปีที่แล้ว

    Any idea what program they use

  • @Hino_55
    @Hino_55 4 ปีที่แล้ว +1

    Key takeaway is:
    The elapsed time for the motion of the object represented in its x & y component motion is the same for both x & y components.
    Well explained Sir David! Thankyou!!!

  • @rheanng1920
    @rheanng1920 6 ปีที่แล้ว +1

    thank u !! my physics textbook nor teacher does this good of a job lol

  • @thecurryoflife3
    @thecurryoflife3 4 ปีที่แล้ว +1

    11:17 How come the time t wasn't squared?

    • @altunartuch5094
      @altunartuch5094 4 ปีที่แล้ว

      Because half of zero is just zero times by t squared is just zero the last part if the equation doesn’t matter

  • @markkaranja11
    @markkaranja11 4 ปีที่แล้ว

    What if we are asked about the horizontal and verticle components of the velocity when the object hits the water?

  • @tusharahmed3151
    @tusharahmed3151 6 ปีที่แล้ว

    aweosome man. very good explanation

  • @shrekkosswampinar7088
    @shrekkosswampinar7088 4 ปีที่แล้ว

    Thank you. This video helped me a lot

  • @elialanaable
    @elialanaable 7 ปีที่แล้ว +2

    what if we needed to find the total distance?

  • @jologendary
    @jologendary 4 ปีที่แล้ว

    can i ask why you multiplied both sides by 2 on the equation of getting the time?

  • @gurkaransingh1922
    @gurkaransingh1922 6 ปีที่แล้ว

    great video ,i understood everything ☺

  • @celebrityfan6870
    @celebrityfan6870 5 ปีที่แล้ว

    At 5:38 you said acceleration downwards is negative.
    How is that possible it is working along with gravity so it has to be positive right?
    Someone pls explain

    • @heavens.sorrow
      @heavens.sorrow 5 ปีที่แล้ว

      I believe it's just written as a negative because acceleration requires a direction so, the negative symbol is just a placeholder per say for down for Voy.

  • @giovannadealca3187
    @giovannadealca3187 3 ปีที่แล้ว

    thanks for it😁

  • @annc6152
    @annc6152 6 ปีที่แล้ว +3

    thank you I love you.

  • @arslan5829
    @arslan5829 2 ปีที่แล้ว

    How do I find the Horizontal, Vertical components of Velocity and Magnitude and direction of its resultant velocity, just as it strikes the water?

    • @arslan5829
      @arslan5829 2 ปีที่แล้ว

      Please Help !

    • @alessandrodornelles9159
      @alessandrodornelles9159 2 ปีที่แล้ว

      Horizontal component of velocity is 5 m/s because there is no acceleration in the x direction
      For vertical component, since you know the time it takes to strike the water and you know the acceleration, you can plug it in the velocity formula (V = v0 + a*t)
      For magnitude you can use the Pythagorean theorem (V^2 = vx^2 + vy^2) and for the direction you can use the arctangent, because arctan(vy/vx) is going to be equal to the angle of the velocity vector

  • @trinitywirth9329
    @trinitywirth9329 4 ปีที่แล้ว

    My saving grace

  • @Dimwol333
    @Dimwol333 6 ปีที่แล้ว

    I love this guy. Good humor and explains in the easiest way. But I was looking for something else. I knew how to solve this problem. I was searching for muzzle velocity. But got caught still. hahah

  • @Physics841
    @Physics841 3 ปีที่แล้ว

    perfect explanation

  • @LinhNguyen-ff3on
    @LinhNguyen-ff3on 5 ปีที่แล้ว

    Thank you this was very helpful!!

  • @connorb7182
    @connorb7182 6 ปีที่แล้ว +3

    10:28 I recommend keeping it as Δx because for the students who have already taken calculus may get dx confused with the notation to integrate.
    Edit: I'm only 13 and I'm watching this lol. I'm learning physics and biochem because there really is nothing else to do I took pre-calc in 4th grade.

    • @breazfreind402
      @breazfreind402 6 ปีที่แล้ว +2

      "Edit: I'm only 13 and I'm watching this lol. I'm learning physics and biochem because there really is nothing else to do I took pre-calc in 4th grade."
      here's a famous quote that i personally made, im also rlly smart i think smarter, see: "I don't care about your start, i care about your end". I heard all these "geniuses", "prodigies" but they become really nothing at the end. I hate the use of "genius" in such a familiar and ordinary word applying to everyone. make something unique and then i will regard, for now i see you as ordinary

    • @breazfreind402
      @breazfreind402 6 ปีที่แล้ว +1

      forgot to mention, you are cringy , self-respecting, idiot, has no friends, thinks his smart but brain says no and so much more and u have the audacity to say words like that make my blood go red

    • @SlowKlone
      @SlowKlone 6 ปีที่แล้ว

      yeah no they won't, there's not even an integration sign. Also, that edit is really cringy dude, nobody cares that you're smarter than other people.

    • @breazfreind402
      @breazfreind402 6 ปีที่แล้ว +1

      to emphasise, your pretentious edit is more larger than your post. shopping list "your mom as a account name" "maximilianus avatar ". 3 months ago you had a different avatar stop being so trendy trapoline

    • @mufidhmuhsin2314
      @mufidhmuhsin2314 5 ปีที่แล้ว

      I am 13 too. Well I do calc too. Shits ain't a big deal

  • @Sam-rg7tg
    @Sam-rg7tg 3 ปีที่แล้ว

    Thank you so much it helped a lot

  • @snapebtwalt
    @snapebtwalt 6 ปีที่แล้ว +2

    THIS WAS SUCH A GREAT VIDEO DAVID > SAL

  • @jhelseaamarixe4475
    @jhelseaamarixe4475 4 ปีที่แล้ว

    do we only give a e -9.8 going upwards if it is in free fall?

  • @coolamazon123
    @coolamazon123 4 ปีที่แล้ว

    What if you are not given the cliff height at all and you are supposed to find it?

  • @isonif2503
    @isonif2503 3 ปีที่แล้ว

    thank you very well explained

  • @bhavanig1543
    @bhavanig1543 2 ปีที่แล้ว

    its just a basic,why the people cant understand this. can u keep formulaes derivating video

  • @luanalazaga
    @luanalazaga 2 ปีที่แล้ว

    why when solving for the distance he didn't squared the time value? I missed something?

  • @starboii568
    @starboii568 5 ปีที่แล้ว

    Why is the acceleration negative if you are going downwards