Terminal velocity

Definition

Terminal velocity is the constant speed that a freely falling object eventually reaches when the resistance of the medium prevents further acceleration. It occurs when the drag force equals the gravitational force acting on the object.

5 Must Know Facts For Your Next Test

1. Terminal velocity depends on the mass, cross-sectional area, and drag coefficient of the falling object.
2. At terminal velocity, the net force on the object is zero because gravitational force and drag force balance each other out.
3. In air, terminal velocity for a human skydiver in a belly-to-earth position is around 120 mph (193 km/h).
4. The drag force is affected by factors such as air density and velocity squared of the object.
5. Objects with larger surface areas reach lower terminal velocities due to greater air resistance.

Review Questions

• What factors determine an object's terminal velocity?
• Explain why an object stops accelerating when it reaches terminal velocity.
• How does changing the shape of an object affect its terminal velocity?

Related terms

Drag Force:

A resistive force exerted by a fluid (e.g., air or water) opposing an object's motion through it.

Gravitational Force:

$$F = mg$$, where $$m$$ is mass and $$g$$ is acceleration due to gravity; it acts downward towards Earth's center.

Newton's First Law:

\$\$F_{net} = ma$$ states that an object at rest stays at rest and an object in motion stays in motion unless acted upon by a net external force.