Question

Which of the following is the mathematical representation of law of conservation of total linear momentum?

(a) dP/dt = 0

(b) dF/dt = 0

(c) dP/dt = Finternal

(d) dF/dt = P

The question was asked during an interview.

I need to ask this question from Linear Momentum of a System of Particles in division System of Particles and Rotational Motion of Physics – Class 11

Answer 1

The correct answer is (a) dP/dt = 0

The best explanation: The law of conservation of linear momentum is derived from Newton’s second law. It states that total linear momentum is constant when external forces add up to zero. Newton’s second law: dP/dt = Fext. Here, Fext must be zero for conservation of linear momentum, thus dP/dt = 0.