Answer the question 1 for the case where air resistance is ?not negligible—where air drag affects motion. Question 1 Someone standing at the edge of a cliff (as in Figure 3.8) throws a ball nearly straight up at a certain speed and another ball nearly straight down with the same initial speed. If air resistance is negligible, which ball will have the greater speed when it strikes the ground below?
Solution 31E The ball which is thrown up will remain in air for a longer time than the one thrown downward. When air resistance is taken into account, this ball will have a speed which will be slowed down during its fall. Finally, it may reach a terminal speed or a constant downward speed. But the ball which is thrown down will be in air for a shorter time and hence its speed will not be slowed down as much as the ball thrown up. So, the ball thrown down will have a greater speed when it strikes the ground.