Terminal Velocity

When something falls through the air, gravity pulls it faster and faster. But air pushes back against the falling object. At some point, the air resistance equals the pull of gravity. The object stops speeding up and falls at a steady speed. This steady speed is called terminal velocity.

How It Works

When you drop a ball, gravity makes it fall faster every second. But as it goes faster, air resistance pushes against it more and more. Eventually the air pushes up as hard as gravity pulls down. The forces balance and the ball stops accelerating. It keeps falling, but at the same speed.

Different Objects, Different Speeds

Terminal velocity depends on the object's size, shape, and weight. A feather reaches terminal velocity quickly because it is light and catches a lot of air. A bowling ball falls much faster before reaching terminal velocity. Skydivers have a terminal velocity of about 120 miles per hour with their arms and legs spread out.

Fun Facts

• A skydiver can change their terminal velocity by changing body position. Going headfirst can reach 200 miles per hour.
• A penny dropped from the Empire State Building would not hurt you because its terminal velocity is only about 30 miles per hour.
• Cats have a lower terminal velocity than humans because of their small size and fluffy fur.

Did You Know?

On the Moon, there is no air, so there is no air resistance and no terminal velocity. If you dropped a feather and a hammer on the Moon, they would hit the ground at the same time. Apollo 15 astronaut Dave Scott actually demonstrated this!