Terminal Speed for Various Objects Falling Through Air
Mass Cross-Sectional Area vT
Object (kg) (m2) (m/s)
Skydiver 75 0.70 60
Baseball(radius 3.7 cm) 0.145 4.2 10-3 43
Golf ball (radius 2.1 cm) 0.046 1.4 10-3 44
Hailstone (radius 0.50 cm) 4.8 10-4 7.9 10-5 14
Raindrop (radius 0.20 cm) 2.4 10-5 1.3 10-5 9.0
A pitcher hurls a 0.145-kg baseball past a batter at 39.5 m/s (= 88 mi/h). Find the resistive force acting on the ball at this speed.
A baseball is dropped from a 28 m high building.
(a) Calculate the speed of the ball just before it hits the ground ignoring air resistance.
(b) Calculate the air drag force that acts on a baseball traveling at this speed. Give your answer as a fraction of the gravitational force that acts on the ball. (In reality the speed of the baseball will be slower because we cannot ignore air resistance for the entire fall.)
R = multiplied by mg?