Question

An automobile travels on a straight road for 40km at 30 km/hr. It then continues in the same director for another 40 km at 60 km/hr. (a) What is the average ... Assume that it moves in the positive x direction.

Answer 1

Answer:

$v_{avg} = 40 km/h$

Explanation:

Time taken by the car to move first 40 km distance

$t_1 = \frac{d}{v}$

here we have

$t_1 = \frac{40}{30}$

similarly the time taken by car to move next 40 km is given as

$t_2 = \frac{40}{60}$

so total time of the motion is given as

$t = t_1 + t_2$

$t = \frac{40}{30} + \frac{40}{60}$

$t = 2 hours$

total distance moved by the automobile

$d = 40 + 40 = 80 km$

so the average speed is given as

$v_{avg} = \frac{distance}{time}$

$v_{avg} = \frac{80 km}{2 hr}$

$v_{avg} = 40 km/h$