A police van moves at 30 km h⁻¹ and fires a bullet in the same direction at a thief's car moving at 192 km h⁻¹. Bullet muzzle speed is 150 m s⁻¹ relative to the van. With what speed does the bullet hit the thief's car as seen by the thief?
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Question

A police van moves at 30 km h⁻¹ and fires a bullet in the same direction at a thief's car moving at 192 km h⁻¹. Bullet muzzle speed is 150 m s⁻¹ relative to the van. With what speed does the bullet hit the thief's car as seen by the thief?

Options

G1 Physics · Accepted Answer

Van speed=30 km h⁻¹=8.33 m s⁻¹. Bullet ground speed=150+8.33=158.33 m s⁻¹. Thief speed=192 km h⁻¹=53.33 m s⁻¹. Relative speed=158.33-53.33=105 m s⁻¹. Option A.