Question

A car at rest ends accelerates for 12 seconds. After this time the car is going 36 m/s. What was its acceleration?

Answer 1

Using the equation of motion:

`a = (v-u)/(t)`

where
`a` is acceleration,
`v` is final velocity,
`u` is initial velocity, and
`t` is time

Given values are:

`t = 12 sec, v= 36 m/s, u = 0` (because initially car was at rest)

Substituting the values in the formula:

`a = (36-0)/(12) = 3 m/s^(2)`

Hence, the acceleration of the car is
`3 m/s^(2)`.

Answer 2

Acceleration is defined as velocity per unit time.

`Acceleration=(Velocity)/(time)`

`a=(dv)/(dt)`

Here, a=acceleartion,

v=velocity=36 m/s

t=time=12 s

`a=(dv)/(dt)`

`a=(36)/(12)`

`a=3 ms⁻²`

A car at rest ends accelerates for 12 seconds. After this time the car is going 36 m/s. So acceleration that is a=3 ms⁻².