Q. A police jeep is chasing with velocity of $45\ km/h$ a thief in another jeep moving with velocity $153\ km/h$. Police fires a bullet with muzzle velocity of $180\ m/s$. The velocity with which it will strike the car of the thief is
A) $150\ m/s$
B) $27\ m/s$
C) $450\ m/s$
D) $250\ m/s$
Explanation
(a) Effective speed of bullet
$=$ speed of bullet + speed of police jeep
$= 180\ m/s + 45\ km/h = (180 + 12.5)\ m/s = 192.5\ m/s$
$Speed\ of\ thief’s\ jeep$ $= 153\ km/h = 42.5\ m/s$
Velocity of bullet $w.r.t.$ thief’s car $= 192.5 - 42.5 = 150\ m/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.