# Science -Physics Chapter 2

## 29 terms

### force

a push or a pull of an object

### net force

the overall force on an object after all the forces are added together

### unbalanced forces

can cause an object to start moving ,stop moving or change direction

### balanced forces

equal forces acting on one oject in opposite directions

### inertia

the tendancy of an object to resist change in its motion

### Newton's first law of motion

an object at rest will stay at rest and an object in motion will stay in motion, unless acted upon by an unbalanced force

### mass

the amount of matter in an object

### force (formula)

mass x acceleration

### newton (measurement)

force required to accelerate 1kg of mass 1m per second per second

force / mass

### friction

the force that one surface exerts on another when the two rub against each other.

### types of friction

sliding, rolling and fluid

### sliding friction

when a solid surface slidees over another

### rolling friction

when an object rolls over another surface

### fluid friction

when an object moves through a liquid or gas

### gravity

force that pulls one object towards another

### free fall

when the only force acting on a falling object is gravity, the object is said to be in.....

### projectile

when an object is thrown horizontally and the only force acting upon it is gravity. the object is a.......

### air resistance

when an object is falling thru air it expirences a type of friction called

### terminal velocity

as an object falls the air resistance increases and and changes the speed of the object. the greatest speed the object reaches is called

### velocity

speed in a given direction

### Law of universal gravitation

force of gravity acts between all objects in the universe

### Newton's Second Law of Motion

the net force of an object is equal to the product of its acceleration and its mass

### Newton's Third Law of Motion

if one object exerts a force on another object then the second object exerts a force of equal strength in the opposite direction on the first object

### momentum

quantity of motion. the product of an object's mass and velocity

mass x velocity

### Law of Concervation of Momentum

total momentum of the objects that interact does not change- unless outside forces act upon the objects

### satellite

any object that travels around another object in space

### centripetal force

any force that causes an object ot move in a circle