Explanation:
Terminal velocity is the speed at which drag force equals weight. If two objects have the same mass (and therefore the same weight), but one has a larger surface area, then the object with the larger surface area will have a lower terminal velocity.
We can show this using the equation for drag force. When drag equals weight:
W = D
mg = ½ρv²CA
Solving for v²:
v² = 2mg / (ρCA)
With m (mass), ρ (air density) and C (drag coefficient) held constant, v decreases as A increases.
