The diagram shows a uniformly accelerating ball. The position of the ball each second is indicated.<image 1>What is the average speed of the ball between 3 and 4 seconds?
['3.0 cm/s', '7.0 cm/s', '3.5 cm/s', '12.5 cm/s']
Average speed = total distance divided by total time = (7 cm)/(1 s) 