A tennis ball (m = 56 g, d = 6.54 cm and cd = 0.6) falls vertically from a 1 km tower (with an initial "zero" speed). 1. What time does the ball take to touch the ground if drag is neglected? 2. What time does the ball take to touch the ground if drag is taken into account? 3. Is your estimated time of question 2: smaller than the actual time speed (m/s) equal to the actual time bigger that the actual time To answer question 2, consider that the following estimation (black dashed curve) of the hyperbolic tangent dependency of velocity is "good enough": terminal velocity (0,0) time (s) mg