Physics Laws & Theorems
Advanced

Kepler's Second Law

A line from a planet to the Sun sweeps equal areas in equal times.

Formula

dAdt=const\frac{dA}{dt} = \text{const}

Variables

ASwept area
tTime

Example

A planet speeds up near the Sun and slows down when far away.

Did You Know?

A planet sweeps equal areas in equal times, so it races fastest when closest to the Sun.

keplerorbitarealaw