### Circular Motion Video 1

### Circular Motion Video 2

# Force of Gravity

- The force of gravity is a force of attraction between any two masses.
- Gravity gets stronger with greater mass, and weaker with greater distance. The equation for this is:

- Make sure you can answer questions such as: If the distance between two masses doubles, what will happen to the force of gravity between them? (Answer: since distance is squared on the bottom, the force will be 1/4 as large.)

# Circular Motion

For an object traveling in uniform circular motion:

- The force and the acceleration are centripetal (pointing towards the center) , and the velocity is tangent to the curve.
- The acceleration is found by using the equation a = v
^{2}/r. - F
_{net }= ma can be replaced by F_{net}= mv^{2}/r. - For a car on a circular track, F
_{net}= ma becomes F_{f}= mv^{2}/r. - For orbits, F
_{net}= ma becomes F_{g}= mv^{2}/r.

Advertisements