Let the distance travelled by car in one round be S km. Therefore total distance travelled by the is 2S km. We know that: V1=30 km/h, v2= 50 km/h speed = distance /time T1= S/30, T2 =S/50 ∴total time= 8S/150 average speed = total distance/total time =2S/8S/150 =37.5 km/h Displacement=0 ∵because the car returns to the same point from where it had started.
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