This deep dive covers Velocity-Time Graphs for Falling Objects 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 3 of 13 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
💪 Velocity-Time Graphs for Falling Objects
Figure 2: Velocity-time graph for a skydiver — note the changing gradient and the effect of opening the parachute
The gradient (slope) of a velocity-time graph tells you the acceleration at any point.
- Steep positive gradient at the start — large resultant force, large acceleration (about 10 m/s²)
- Decreasing gradient — drag is increasing, resultant force decreasing, acceleration decreasing
- Zero gradient (horizontal line) — terminal velocity reached, resultant force = 0, acceleration = 0
- Negative gradient after parachute opens — drag suddenly much greater than weight, so deceleration occurs
- New horizontal line at lower speed — new (lower) terminal velocity with parachute open
The area under a velocity-time graph gives the distance travelled. This is useful for calculating how far a skydiver has fallen at any point.
Quick Check: A skydiver is falling at a constant velocity of 55 m/s. What is the resultant force acting on them?
Zero. At terminal velocity, weight equals drag, so the resultant force is zero. This means acceleration is also zero (F = ma: if F = 0, a = 0).
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.