4. a driver travels 135 km, east in 1.5 h, stops for 45 minutes for lunch,
and then resumes driving for the next 2.0 h through a displacement
of 215 km, east. what is the driver's average velocity?

an explanation too

The driver's average velocity is 82.35 km/h.

Explanation:

Given:

The motion of the driver can be divided into 3 parts:

i. Displacement of the driver in 1.5 hours = 135 km

ii. Rest for 45 minutes.

iii. Displacement in next 2 hours = 215 km

The direction of motion remains same (east).

Now, total displacement of the driver is, km.

Rest time is 45 minutes. Converting it to hours, we need to use the conversion factor hour.

So, 45 minutes in hours is equal to hours.

Now, total time taken for the complete journey is,

Average velocity is given as:

Therefore, the driver's average velocity is 82.35 km/h