A car travels north at 30.0 m/s for 10.0 min. It then travels south at 40.0 m/s for 20.0 min. What are the total distance that car travels and its displacement?

A car travels north at 30.0 m/s for 10.0 min. It then travels south at 40.0 m/s for 20.0 min. What are the total distance the car travels and its displacement?

Let DS & DP denote net distance & net displacement of the car.

Hence from above data we get following relations,

DS = 10*60*30 + 20*60*40

or DS = 18000 + 48000

or DS = 66000 (m) = 66 (km) [Ans]

DP = + 10*60*30 (NORTH) - 20*60*40 (SOUTH) [assuming NORTH as +ve]

or DP = + 18000 (NORTH) - 48000 (SOUTH)

or DP = - 30000 (SOUTH) = - 30 (km) (SOUTH)