Sarah is coasting on her roller skates at a constant velocity of 20.m⋅s−1 to the right when she collides head-on with Jane who is standing nearby. After the collision, the two girls move away, tangled together with the same velocity. Sarah is 40.kg and Jane is 60.kg . a. State the principle of conservation of momentum. (2) b. Determine the final velocity of Sarah and Jane. (2) c. Calculate the change in the kinetic energy of the system. (3) d. State and explain whether the collision is elastic or inelastic. (2)
