Question

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 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

Answer 1

Answer: (A)

150 m/s

Answer 2

Effective speed of the bullet

= speed of bullet + speed of police jeep

$= 180 ⥂ \mspace{6mu} m/s + 45\mspace{6mu} km/h = (180 + 12.5)\mspace{6mu} m/s = 192.5\mspace{6mu} m/s$

Speed of thief ’s jeep $= 153km/h = 42.5m/s$

Velocity of bullet w.r.t thief ’s car$= 192.5 - 42.5$=150m/s