At terminal velocity, we can write an equation linking the forces:
Weight = Drag force
mg = k v² (where k is a drag constant depending on shape, size and fluid density)
Rearranging to find terminal velocity:
v_terminal = √(mg / k)
This tells us:
- If mass doubles, terminal velocity increases by a factor of √2 (about 1.41 times)
- If the drag constant k doubles (e.g. by doubling surface area), terminal velocity decreases by √2
This is why a heavier person falls faster even with the same parachute — their higher weight requires a higher speed before drag is large enough to balance it.
This higher tier covers Higher Tier: Quantitative Analysis of Terminal Velocity within Terminal Velocity for GCSE Physics. Revise Terminal Velocity in Extra Topics for GCSE Physics with 13 exam-style questions and 11 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 10 of 13 in this topic. This section is most useful once the core foundation idea is secure, because it adds the detail that pushes answers higher.
Practice questions for Terminal Velocity
An object reaches terminal velocity when falling through air. Which statement correctly describes the forces at terminal velocity?
Explain how a skydiver reaches terminal velocity after jumping from a plane. Include changes to forces and acceleration in your answer.