1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Projectile Motion 2D - Spring Launched

  1. Feb 13, 2014 #1
    Projectile Motion 2D -- Spring Launched

    There is this ball launched from a slingshot. Given the mass is 0.9 kg at the angle 60° to the horizontal, with k=750 N/m and is stretched by length l = 0.6 m. The ball is shot 1 m above the ground. (g=10 m/s2).

    The questions are to derive the equation describing the velocity and trajectory with the aerodynamic drag negligible.

    My approach is first to find the acceleration in x and y direction.
    F = k.x = 750x0.6 = 450 N
    Fx = F cos 60 = 389.71 N, Fy = F sin 60 = 225 N

    Horizontal:
    Fx = m*ax
    ax = 250 m/s2

    Vertical:
    Fy - mg = m*ay
    ay = 423.01 m/s2

    Then I find the Velocity
    Vx = Vox + 250t
    Vy = Voy + (423.01-10)t = Voy + 413.01t

    My problem is now finding the initial Velocity Vo. I was thinking of using Energy principal but then I am stuck with the velocity of the ball at certain point, thus, I was not able to solve it.
     
  2. jcsd
  3. Feb 13, 2014 #2
    The initial velocity is zero.
     
  4. Feb 13, 2014 #3

    PhysicoRaj

    User Avatar
    Gold Member

    So the initial velocity will be nonzero.
     
  5. Feb 13, 2014 #4
    Oh yes that's right my bad. Use an energy equation 1/2kx^2 = 1/2 mv(0)^2.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Projectile Motion 2D - Spring Launched
  1. Projectile motion (Replies: 2)

  2. Projectile Motion (Replies: 1)

  3. Projectile motion (Replies: 5)

Loading...