Question

A car is moving on a straight road. The velocity of the car varies with time as shown in figure. Initially (at $t=0$), the car was at $x=0$, where, $x$ is the position of the car at any time $t$.
The time interval during which the car is retarding can be:

• A. $t=50$ $s$ to $t=70$ $s$
• B. $t=30$ $s$ to $t=50$ $s$
• C. $t=30$ $s$ to $t=60$ $s$
• D. $t=10$ $s$ to $t=20$ $s$

Answer 1

Answer: (B)

$t=30$ $s$ to $t=50$ $s$

Retardation occurs when the magnitude of velocity is decreasing with increase in time. This occurs in time intervals $30<t<50$ and $60<t<70$. In the given options, option B satisfies the criteria.