Question

A car covers half of the distance with speed $60km/hr$ and rest of the half with speed $30km/hr$ . The average speed of the car is -

• A. $45km/hr$
• B. $40km/hr$
• C. $20.0km/hr$
• D. $50km/hr$

Answer 1

Answer: (B)

$40km/hr$

Let the total distance is $s$ and the total time is $t$.

The average velocity is given as,

$v=\frac{s}{t}$

$v=\frac{s}{t_1+t_2}$

$v=\frac{s}{\frac{\left(s/2\right)}{60}+\frac{\left(s/2\right)}{30}}$

$v=40km/hr$

Thus, the average speed is $40km/hr$.