# Draw a graph v(t) for body which is moving 15 min with a velocity of 20km/h. Then this body stops for 5 min and then continue to move again for 10 min with velocity of 25 km/h. What is the average velocity of the body?

May 24, 2016

Graph as below.
$18. \dot{3} k m / h$

#### Explanation:

The graph of $v \left(t\right) \text{ Vs } t$ is as below

To calculate average velocity we proceed as follows, after converting time to hours
1. Total time of travel $= \frac{30}{60} = 0.5 h$
2. Total distance traveled $= 20 \times \frac{15}{60} + 0 \times \frac{5}{60} + 25 \times \frac{10}{60}$
$= 5 + \frac{25}{6} = \frac{55}{6} k m$
3. $\text{Average velocity"="Total displacement"/"Time of travel}$
$= \frac{\frac{55}{6}}{0.5} = \frac{55}{3} = 18. \dot{3} k m / h$