Answer:
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, [tex]D_{Total}=135+215=350[/tex] km.
Rest time is 45 minutes. Converting it to hours, we need to use the conversion factor [tex]1\textrm{ min} = \frac{1}{60}[/tex] hour.
So, 45 minutes in hours is equal to [tex]\frac{45}{60}=0.75[/tex] hours.
Now, total time taken for the complete journey is, [tex]\Delta t=1.5+\frac{45}{60}+2=1.5+0.75+2=4.25\textrm{ h}[/tex]
Average velocity is given as:
[tex]v_{avg}=\frac{\textrm{Total displacement}}{Total time}=\frac{350}{4.25}=82.35\textrm{ km/h}[/tex]
Therefore, the driver's average velocity is 82.35 km/h
