Identify the type of inertia experienced by the brain,when
$(a)$ the head is hit suddenly with a stick.
$(b)$ a car is suddenly made to stop using brakes.
$(c)$ a boxer punches another boxer in the face.

(N/A) Inertia of rest: When the head is hit suddenly,the skull moves forward due to the impact,but the brain,due to its inertia of rest,tends to remain in its original position,causing it to strike against the inner wall of the skull.
$(b)$ Inertia of motion: When a car stops suddenly,the body and the brain are in a state of motion. Due to the inertia of motion,they continue to move forward even after the car has stopped,causing the brain to hit the front part of the skull.
$(c)$ Inertia of rest: When a boxer is punched,the head is pushed backward suddenly. The brain,due to its inertia of rest,tends to stay in its initial position,causing it to strike against the back wall of the skull.