Question

A jeep moves at uniform speed of $60km{h}^{-1}$ on a straight road blocked by a wall. The jeep has to take a sharp perpendicular turn along the wall. A rocket flying at uniform speed of $100km{h}^{-1}$ starts from the wall towards the jeep which is $30km$ away. The rocket reaches the windscreen and returns to wall. Total distance covered by the rocket is

• A. $100km$
• B. $50km$
• C. $37km$
• D. $75km$

Answer 1

Answer: (C)

$37km$

Time taken by rocket and jeep to meet
$Time=\frac{Distance}{V_{rel}}=\frac{30}{160}=\frac{3}{16}$
Distance travelled by the rocket is given as velocity times the time taken
$s=100\times time=18.75km$
Thus we get the total distance as twice this value
$=2\times 18.75km=37.5km$