Question

A car is going 8 meters per second on an access road into a highway

and then accelerates at 1.8 meters per second squared for 7.2
seconds. How fast is it then going?

Answer 1

20.96 m/s is the final speed.

Explanation:

Given that:

Initial speed of the car = 8 m/s

Acceleration of the car = 1.8 m/
`s ^(2)`

Time for which the car accelerates = 7.2 seconds

To find:

The speed of car after accelerating for 7.2 seconds at an acceleration of 1.8 m/
`s ^(2)` = ?

Solution:

First of all, let us have a look the formula given for the final velocity of an object with given initial speed, acceleration and time:

`v=u+at`

Where
`v` is the final speed of object

`u` is the initial speed of an object

`a` is the acceleration of object and

`t` is the time

Here,
`u = 8\ m/s`

`a = 1.8\ m/s^(2)` and

`t = 7.2\ seconds`

To find:

`v = ?`

Let us put all the given values in the formula:

`v =8+1.8 * 7.2\\\Rightarrow v =8+12.96\\\Rightarrow \bold{v =20.96\ m/s}`

So, the answer is:

20.96 m/s is the final speed.