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

`v_(avg) = 40 km/h`

Step-by-step explanation:

Time taken by the car to move first 40 km distance

`t_1 = (d)/(v)`

here we have

`t_1 = (40)/(30)`

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

`t_2 = (40)/(60)`

so total time of the motion is given as

`t = t_1 + t_2`

`t = (40)/(30) + (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) = (distance)/(time)`

`v_(avg) = (80 km)/(2 hr)`

`v_(avg) = 40 km/h`