AIR RESISTANCE AND TERMINAL VELOCITY
3 marks · EasyA tennis ball is dropped from a balcony. It falls straight down through the air.
State the two forces acting on the tennis ball as it falls.
As the ball falls faster, describe what happens to the size of the air resistance.
Eventually the ball falls at a constant speed. What is the name of this constant speed?
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) Weight (gravity) and air resistance (drag)
(b) Air resistance increases as the ball falls faster (as speed increases, air resistance increases)
(c) Terminal velocity
Common mistakes: Omitting air resistance; Describing only weight; Incorrect definition of terminal velocity
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Both forces correctly identified: weight (gravity) and air resistance (drag)
B1 (b) · 1 mark · Correctly states that air resistance increases (with speed/falling faster)
B1 (c) · 1 mark · Names the constant speed as terminal velocity
Worked solution
a) The two forces acting are:
- Weight (the force of gravity)
- Air resistance (drag)
b) As the ball falls faster, the air resistance increases.
c) The name of the constant speed is terminal velocity.