A motor car moving with a uniform speed of $20\,m/\sec $ comes to stop on the application of brakes after travelling a distance of $10\,m$ Its acceleration is..........$m/{\sec ^2}$
$20$
$ - 20$
$ - 40$
$ + 2$
A motor car moving with a uniform speed of $20\,m/\sec $ comes to stop on the application of brakes after travelling a distance of $10\,m$ Its acceleration is..........$m/{\sec ^2}$
From ${v^2} = {u^2} + 2aS$
$⇒$ $0 = {u^2} + 2aS$
$⇒$ $a = \frac{{ - {u^2}}}{{2S}} = \frac{{ - {{(20)}^2}}}{{2 \times 10}} = - 20m/{s^2}$
$⇒$ $0 = {u^2} + 2aS$
$⇒$ $a = \frac{{ - {u^2}}}{{2S}} = \frac{{ - {{(20)}^2}}}{{2 \times 10}} = - 20m/{s^2}$