Question

A body starts to slide over a horizontal surface with an initial velocity of 0.5 m/s. Due to friction, its velocity deceased at the rate of 0.5 m/$s^2$ . How much time will it take for the body to stop?

Answer 1

Step 1: Given data

Initial velocity($u$) = $0.5m{s}^{-1}$

As, the velocity of the body is decreasing, the acceleration will be negative.

The negative acceleration($a$) in the body= $-0.5m{s}^{-2}$

As, the body stops,

Final velocity($v$) of the body= $0$

Step 2: Calculation of time the body will take to stop:

We know from the equation of motion

$v=u+at$

Putting all the values

$0=0.5m{s}^{-1}-0.5m{s}^{-2}\times t$

$0.5\times t=0.5$

$t=\frac{0.5}{0.5}$

$t=1sec$

Thus,

In $1sec$ the body will stop.