Question

A sprinter needs 4 seconds to come to a rest after crossing the finishing line at a speed of 8m/s. What is his acceleration?​

Answer 1

`a=2m/s^2`

Explanation:Explanation: The formula for acceleration is
`a=(change\ in\ velocity)/(Total\ time)`.

Here the initial velocity is
`0m/s`. The object moves with uniform acceleration.

and the final velocity is
`8m/s`.

the time the sprinter needs
`=4s`.

hence, we have,

`a=(final\ velocity-initial\ velocity)/(Total\ time)\\`

`a=(8-0)/(4)`

`a=(8)/(4)`

`a=2m/s^2`.

Hence, the acceleration is
`a=2m/s^2` .