# Chapter 2 1-4 Science test

## 28 terms

### force

A push or a pull.

### static, sliding, rolling, and fluid

4 types of friction?

### opposes motion

How does friction affect motion?

### inertia

The tendency of an object to resist a change in motion.

### momentum

The product of an object's mass and velocity.

### Mass times velocity

Formula of momentum?

### amount of mass and speed

What does momentum depend on?

### Mass

amount of matter in an object

### Net force divided by mass

Formula of acceleration

### balanced forces

Equal forces acting on an object in opposite directions, no change in motion.

### unbalanced forces

Forces that produce a non-zero net force, which changes motion.

### Newton's first law

An object at rest remains at rest, an object in motion remains in motion, unless acted upon by an outside force. (also called law of inertia)

### Newton's second law

Acceleration depends on net force and mass.

### Newton's third law

For every action there is a equal and opposite reaction.

### centripetal force

a force that keeps an object moving in an circle.

### satellite

Any object that travels around another object in space.

### newton

the SI unit of force

### lemon

every newton is measured to be the same as a...

### terminal velocity

when a falling object reaches this when forces of gravity and air resistance are balanced.

### gravity

the force that pulls and accelerates objects toward the Earth.

if forces act together we do what to the net force?

### subtract the smaller one from the larger one

if forces act against each other what do we do to the net force?

### no motion

if forces are equal and opposite to each other what happens to the object?

### weight

________ is the gravitational force exerted on an object.

### one newton

____ ________ equal the force required to accelerate 1 kilogram of mass at 1 meter per second ²

### free fall

when only gravity is acting upon a falling object.

### air resistence

the kind of friction that slows a falling object

### friction

the general term for the force that one surface exerts on another when they rub against each other