Two identical clay spheres of mass move toward each other on a frictionless…
PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
Two identical clay spheres of mass M move toward each other on a frictionless horizontal surface with equal speeds v and collide head-on, sticking together. Which statement best describes the kinetic energy of the system immediately after the collision compared to immediately before the collision?
(a) The kinetic energy is the same as before, because momentum is conserved in the collision.
(b) It is one-half of the initial value because the mass of the system doubles.
(c) It is zero because the combined object is at rest after the collision.
(d) It is one-quarter of the initial value because the combined mass is 2M and the speed after the collision is v/2.