Question

A body moves with a constant velocity of 20 m/s. The mass of the body is 2 kg. What is the unbalanced force acting on the body?​

Answer 1

answer : zero

explanation : according to Newton's 2nd law, force acting on body is the rate of change of linear momentum of body.

i.e., F = dP/dt = d(mv)/dt = m × dv/dt

= ma , a is acceleration of body.

hence, force is the product of mass and acceleration.

a/c to question, A body moves with a constant velocity of 20m/s. it means, velocity of body doesn't change with respect to time.

so, acceleration of body , a = (v - u)/t = (20 - 20)/t = 0.

hence, force acting on the body , F = ma

hence, force acting on the body , F = ma= 2kg × 0 = 0 N

Answer 2

Zero is the answer.

hope, I am correct