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Homework Help: Need help with projectiles launched at an angle

  1. Nov 6, 2008 #1
    Alright, I get how to get projectiles launched horizontally, but today our teacher wasn't even there and for some reason without going over the lesson he assigned us homework...
    so here I am. I just need to basicly know how to do this. I have 3 example problems from my homework. if you can do it thats great, but I would also like to know how.

    1) In a scene in an action movie, a stuntman jumps from the top of one bulding to the top of another buliding 4.0 meters away. after a running start, he leaps at a velocity of 5.0 m/s at an angle of 15 degreeswith respect to the flat roof. will he make it to the other roof which is 2.5 m shorter than the bulding he jumps from?

    2) A golfer hits a gold ball at an angle of 25 degrees to the ground. if the golf ball covers a horizontal distance of 301.5 m, what is the balls max height?

    3)a baseball is thrown at an angle of 25 degrees relative to the ground at a speed of 23 m/s. if the ball was caught 42 m from the thrower, how long was it in the air. how high did the ball travel before being caught?
  2. jcsd
  3. Nov 6, 2008 #2


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    Homework Helper

    No one here is just going to do these for you, it is against forum rules. You need to show some effort yourself. Do you have a textbook to refer to? First, draw a diagram. Since this is two dimensional, you will need to resolve the motion into its horizontal and vertical components. This site illustrates the motion: http://library.thinkquest.org/2779/Even_more.html

    See what you can come up with.
  4. Nov 6, 2008 #3
    I never asked anyone to do it. if they did it would help but those were just examples. I basiclly just need help on how to like go through a problem like that. Like I said I can do horizantal projectals, but we just started angled launches and our teacher didnt even teach us the section because he was gone. He taught us kind of different too, we make like X and Y tables if you guys do that also? Any help?
  5. Nov 6, 2008 #4


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    Homework Helper

    In your first post:
    To me, this statement looks like you are asking someone to do it.

    Yes, making x and y tables is useful. Did you look at the link I gave you?
    Do you know how to resolve a vector into its components? You need to know this before you can start these problems.
    This stuff might be useful for you to look over:

    http://www.ac.wwu.edu/~vawter/PhysicsNet/Topics/Vectors/ProjectilePsolve/PMPSolveRelPhys.html#FundamentialFreeFallEquations [Broken]

    See if it helps, it can do a better job of explaining this than I can since it has diagrams and I don't know what you know. Read through it and ask questions if you get stuck on something.
    Last edited by a moderator: May 3, 2017
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