AS Daily A Level Physics question
A skydiver falls at terminal velocity before opening a parachute, then opens it and waits until a new steady descent is reached. Assume the skydiver’s weight is unchanged. Which statement must be true when comparing the motion at terminal velocity before and after the parachute is opened?
Answer
The correct answer is D.
Correct: D — In both cases at terminal velocity the drag equals the weight, and the parachute gives a lower terminal speed. At terminal velocity the resultant force is zero, so drag balances weight; the increased area with the parachute means this balance occurs at a lower speed. A The skydiver does slow just after opening, but once the new terminal velocity is reached drag no longer exceeds weight. B At terminal velocity acceleration is zero, not upward. C Even with a lower speed the larger area increases drag so that it still equals weight at terminal velocity; drag is not less than weight in steady descent. D This matches Newton’s laws and the effect of increased drag area on terminal speed.