Free fall refers to motion under the influence of gravity only. In other words, the mass experiences only the gravitational pull *mg*. Air resistance (and all the other forces) are absent or negligibly small.

It follows from Newton’s 2^{nd} Law that all masses, heavy or light, free falls at the same rate.

This is why *g* is called the acceleration of free fall. Its value is roughly on the surface of Earth.

If a mass is dropped from rest, the *v-t* and *s-t* graphs (↓ +ve sign convention) of the motion will be as follow:

*v-t* graph is a straight line graph with gradient corresponding to 9.81 m s^{-2}.
*s-t* graph is a quadratic curve, with a steepening gradient corresponding to increasing speed.

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**Demonstrations **

Free Fall (Apollo 15, Brian Cox and BRAINIAC)

**Concept Test**

0226

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