Physics please help cant figure this out
posted by joseph .
starting with an initial speed of 5.00 m/s at a height of 0.265 m, a 1.75 kg ball swings downward and strikes a 4.45 kg ball that is at rest, as the drawing shows.
(a) Using the principle of conservation of mechanical energy, find the speed of the 1.75 kg ball just before impact.
(b) Assuming that the collision is elastic, find the velocities (magnitude and direction) of both balls just after the collision.
(1.75 kg ball)
(4.45 kg ball)
(c) How high does each ball swing after the collision, ignoring air resistance?
(1.75 kg ball)
(4.45 kg ball)

I am wondering what you are having difficultly with. I will be happy to critique your thinking.

im just not sure what formula exactly to use to solve each part a,b, and c

babi

A 0.75{\rm kg} ball, attached to the end of a horizontal cord, is rotated in a circle of radius 1.7m on a frictionless horizontal surface