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Animated version of Newton's famous drawing dealing the free fall of a body. Free fall and the launching of an object into orbit are both governed by the same theory of gravity.

The '+' and '-' buttons enable you to observe different cases, from free fall (initial velocity zero) to escape velocity (11.3 km/s starting from the ground.)

Frictional effects are negligable and only the force due to gravity is acting.

**Click **on 'Plus' or 'Minus' to set the initial speed of the cannon ball.

- To understand how to place an object in orbit.
- To show that circular motion is a special case of an elliptical orbit.

- cannon
- escape
- free fall
- gravitation
- gravity
- newton
- projectile
- rocket
- satellite
- speed
- the placing of a satellite in orbit
- trajectory
- velocity

Gravity is a **force**. Two bodies of **mass** posses a mutual attraction for each other.

The **intensity** of the attractive force (in N) depends on the values of the masses (in kg) and the **distance** (r)…