Answer to Question #39664 in Mechanics | Relativity for vinay kumar

Question

a) A particle of mass 4.0 kg, initially moving with a velocity of 5.0m/s collides elastically
with a particle of mass 6.0 kg, initially moving with a velocity of -8.0m/s.What are
the velocities of the two particles before and after the collision in the centre of mass
frame of reference? What are the velocities of the two particles after the collision in the
laboratory frame?
b) A 30.0 kg girl stands at the rim of a merry-go-round that has a moment of inertia of
500kgm^2 and a radius of 3.00 m. The merry-go-round is initially at rest. The woman
then starts walking around the rim clockwise at a constant speed of 2.0m/s .
i) In what direction and with what angular speed does the merry-go-round rotate?
ii) How much work does the girl do to set herself and the merry-go-round into motion?