Proposition 34 Theorem 10

Proposition 34 Theorem 10

If BED is a parabola, the speed of a falling body in any place C will be equal to the speed by which a body uniformly draws a circle around centre B at half the interval BC.

Cor. 7, Prop. 16 says that the speed of a body in a parabola RPB around the center S in any place P, is equal to the body’s speed uniformly tracing a circle around the same centre S at half the interval SP.

This proposition is proven by reducing the width CP of the parabola infinitely so as the parabolic arc PfB coincides with the line CB.

• The centre S with vertex B, and the interval SP with the interval BC, and