# Chpt. 3 Gravity

## 10 terms

### gravity

the attractive force between two objects, which depends on the masses and distance between them

### 4 basic forces

gravity, electromagnetic force, strong nuclear force, weak nuclear force

### Law of Universal Gravitation

this equation allows the force of objects to be determined.
F = (constant) G X ((mass 1) x (mass 2)) /
distance squared

### Range of Gravity

as the distance increases between objects, the gravity becomes weaker. however, gravity never disappears, it is a long-range force

### Force of Earth's Gravity

Force of gravity (N) = Mass (kg) X acceleration of gravity (m/s2)
F = mg

### Weight

the gravitational force exerted on an object

### Weight Formula

weight (N) = mass (kg) X acceleration of gravity (m/s2)
W = mg

### horizontal motion

the forward motion when you throw a ball

### vertical motion

the downward motion when gravity pulls the ball to the ground

### centripetal force

acceleration toward the center of a curve or circular path. when water stays in a bucket as you swing it in a circle