Asked by Anonymous

What is the kinetic energy of an ideal projectile of mass 19.4 kg at the apex (highest point) of its trajectory, if it was launched with an initial speed of 29.2 m/s and at an initial angle of 46.9° with respect to the horizontal?
Answered by bobpursley
Initial KE=finalKE + PE at highest point

Now, the velocity at the top is only horizontal, or 29.2*cos46.9

final KE=1/2 m (29.2*cos46.9)^2