Question

1. which of the following is true about a perfectly inelastic collision. a. (vec{v}_{f1}=vec{v}_{f2}) c. kinetic energy is not conserved b. (c_{r}=0) d. all of the above

Explanation:

• In a perfectly inelastic collision, the two colliding objects stick together after the collision. So, their final velocities are equal (\(\vec{v}_{f1}=\vec{v}_{f2}\)).
• The coefficient of restitution (\(C_R\)) which is defined as \(C_R=\frac{\text{relative velocity of separation}}{\text{relative velocity of approach}}\). In a perfectly inelastic collision, there is no separation, so \(C_R = 0\).
• Kinetic energy is not conserved in an inelastic collision (part of the kinetic energy is converted into other forms of energy like heat, sound, and deformation energy).

Answer:

D. all of the above