Terminal Velocity
Air resistance balances weight, so falling speed levels off.
About this topic
As an object falls through air, drag increases with speed. Eventually the upward drag equals the downward weight, the net force becomes zero, acceleration stops, and the object falls at constant terminal velocity.
At the start of a fall the speed is small, so drag is small and the acceleration is nearly g. As speed climbs, drag grows, and the acceleration shrinks until it reaches zero. Terminal velocity is larger for heavy, compact objects and smaller for light objects with a large area.
A skydiver reaches about 55 m/s spread-eagle; opening a parachute raises drag and slows to a safe 5 m/s or so. Head-down, a skydiver can reach 90 m/s. Raindrops fall at a few metres per second rather than hitting like bullets, and a feather quickly reaches a tiny terminal speed. Parachutes, seeds with wings and even coffee filters falling in stacks all show the effect.
Misconception: at terminal velocity the object is not stopped, nor is gravity switched off; the forces are simply balanced, so velocity stays constant. Also, the object does not slow down on reaching it, unless the drag later increases.
Key ideas
- Drag grows with speed
- Net force becomes zero
- Parachutes lower terminal speed
Quick check
Use cases: where Terminal Velocity helps
- Homework: review the key idea behind Terminal Velocity before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Terminal Velocity without notes.
- Visual learning: play with the interactive lab to see how Terminal Velocity changes when you adjust its inputs.
- Teaching a friend: explain Terminal Velocity in your own words, then compare your version with the key ideas.
The same laws describe car crashes, sports, satellites and everyday machines.
Frequently asked questions
What is Terminal Velocity?
Air resistance balances weight, so falling speed levels off.
What will I learn in Terminal Velocity?
Drag grows with speed. Net force becomes zero. Parachutes lower terminal speed.
Is Terminal Velocity part of Physics?
Yes. It is one of 150 Physics topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Terminal Velocity lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Terminal Velocity?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.