Question

A police van moving on a highway with a speed of 30 km h–1 fires a bullet at a thief’ car speeding away in the same direction with a speed of 192 km h–1 . If the muzzle speed of the bullet is 150 m –1 , with what speed does the bullet hit the thief’ car? (Note: Obtain that speed which is relevant for damaging the thief’ car).

Answer 1

Speed of the police van, vp = 30 km/h = 8.33 m/*

Muzzle speed of the bullet, vb = 150 m/*

Speed of the thief’ car, vt = 192 km/h = 53.33 m/

Since the bullet is fired from a moving van, its resultant speed can be obtained as: = 150 + 8.33 = 158.33 m/*

Since both the vehicles are moving in the same direction, the velocity with which the bullet hits the thief’ car can be obtained as: vbt = vb – vt = 158.33 – 53.33 = 105 m/