Question

People sitting in a moving bus experience a jerk when the bus stops. This is due to _____

(a) Inertia of motion

(b) Inertia of rest

(c) Inertia of turning

(d) Inertia of acceleration

The question was posed to me in an interview for job.

My doubt stems from Newton’s First Law of Motion in chapter Laws of Motion of Physics – Class 11

Answer 1

Right answer is (a) Inertia of motion

To explain: When the bus stops, the people sitting in it experience a jerk. This is because, while the bus was moving, the people were moving with it. Hence, they were having an inertia of motion. When the bus stops, the inertia of the bus changes from that of motion to that of rest. But the inertia of the people still remains that of motion. Hence, they experience a jerk.