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!

Physics -Work probelm

  1. Oct 28, 2004 #1
    i need help on this problem. thx

    A 47.0 kg projectile is launched with an initial speed of 72.0 m/s and an angle of 39.8° above the horizontal. The projectile lands on a hillside 7.15 s later. Neglect air friction. (a) What is the projectile’s kinetic energy at the highest point of its trajectory? (b) What is the height of the impact point? (c) What is its total energy just before it hits the hillside?
  2. jcsd
  3. Oct 28, 2004 #2


    User Avatar
    Science Advisor
    Homework Helper

    For a) Use an energy approach (obiousvly).

    and [itex]E=K+V[/itex].
    You know E from the initial conditions.
    At the highest point the velocity in the y-direction is zero.

    b) I'd look at the y-component only and write the height as function of time. Then find the height of the impact point.

    c) Use conservation of energy again.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Physics -Work probelm
  1. A Probelm To far (Replies: 2)

  2. Help with a probelm (Replies: 12)

  3. Physics probelm 23 (Replies: 4)

  4. Equilibrium Probelm (Replies: 3)