Question

A 2.0 kg body moving with a velocity of 4m/s

along a positive x-direction collides in a perfectly

elastic collision with a 1.0kg body witch is initially

at rest. after collision the 2.0kg boy is observed to

be travelling at 30 degrees with its original

direction. Find

a. the direction and magnitude of the velocity of

the 1.0 kg body and

b. the magnitude of the velocity of the 2.0 kg

body?

need help here, thanks.