You are a secret agent and find that you have been pushed out of an airplane without a parachute. Fortunately, you are wearing a large overcoat (as secret agents often do). Thinking quickly, you are able to spread out and hold the overcoat so that you increase your overall area by a factor of two.
If your terminal velocity would be 45 m/s without the coat, what is your new terminal velocity with the coat?
1 answer
The aerodynaminc drag force equals weight at the terminal velocity. Drag force is proportional to the square of the velocity, and the first power of the area. If area doubles, the velocity decreases by a factor of 1/sqrt2 = 0.707, to keep the drag force the same. The new terminal velocity is 45/sqrt2 = 31.8 m/s
1 answer