OnlineCBT
Physics · MOTION IN A STRAIGHT LINE
हिन्दीA police van moving on a highway with a speed of \( 30\text{ km h}^{-1} \) fires a bullet at a thief's car speeding away in the same direction with a speed of \( 192\text{ km h}^{-1} \). If the muzzle speed of the bullet is \( 150\text{ m s}^{-1} \), with what speed does the bullet hit the thief's car?
Correct answer · Option 1
\( 105\text{ m s}^{-1} \)
Explanation
Van speed \( v_P = 30 \times \frac{5}{18} = \frac{25}{3}\text{ m/s} \). Thief car speed \( v_T = 192 \times \frac{5}{18} = \frac{160}{3}\text{ m/s} \). Absolute bullet speed \( v_b = 150 + \frac{25}{3} = \frac{475}{3}\text{ m/s} \). Relative speed \( v_{bT} = v_b - v_T = \frac{475}{3} - \frac{160}{3} = 105\text{ m s}^{-1} \).
