A man walks 240m in 30s & then walk back 140m toward the starting point in the next 35s. What is the average speed and velocity?
Recall that the speed is the absolute value of velocity.The average speed is (240 +140)/(35+30)= 380 / 65 = 5.85 m/s
Call the direction of the first 30s move "positive". Since during next 35s the man moves in "negative" direction, the average velocity is (240 - 140)/(35+30)= 100 / 65 = 1.54 m/s in positive direction.