Question

A construction worker assisting in the paving of a street drives a heavy roller back and forth over the newly paved area to smooth the asphalt. The section of street being paved is 100 m long and the roller operator drives from the east end to the west end of the street and back again 20 times during paving operation. A one-way trip (100 m) takes driver 60 seconds, and reversing direction at each end takes 5 seconds. Assuming that the roller ends up at its starting point after the 20 round trips, what was the average speed of the roller? What was the average velocity of the roller?

Answer 1