How fast must a 0.142-kg baseball move in order to have the same momentum as the bus?

Momentum is the product of mass and velocity of a body. In this case, the bus has a mass of 18200 kg and moving with a velocity of 10 m/s.
Therefore, the momentum of the bus will be, 18200×10 = 182,000 kgm/s.
Thus a ball of mass 0.142 kg will require to travel with a speed of;
            = 182000/0.142
            = 1.282 ×10∧6 m/s to have the same momentum with the bus.

The correct answer is  "c".  it is "c" because melting is an endothermic change, and endothermic get's energy from surroundings.