# Could anyone please help me with part F?

##### 2 Answers

Please see the explanation below.

#### Explanation:

The velocity is constant at

Therefore,

The acceleration is

The instantaneous acceleration at

#### Explanation:

According to the figure we have a constant speed until 30 sec, at which point the movement descelerates, so that the speed changes constantly from 60 km/h to 0 km/h in 10 sec. (from 30 to 40 sec.).

Acceleration is speed change per second, i.e.

We, therefore need to convert the speed from

(60 km = 60 000 m, and there are 3600 sec. in 1 hour)

Therefore

The figure shows that the acceleration is constant from 30 to 40 sec. The instantaneous acceleration at