8th Grade Physics

Acceleration

how speed or direction changes with time; can be positive (speeding up) or negative (slowing down) or turning a corner

Balanced Force

Net force is zero and the motion of the object does not change.

Friction

The force between objects that resists motion - always slows down motion

Newton

A measurement of force

Mass

The total amount of matter in something.

Energy

the ability to do work or cause a change

Force

push or pull; causes objects to move

Net Force

The sum of all the forces acting on an object

Gravity

A force that pulls objects together

F = m x a

Formula for Force

Distance vs Time Graph

Shows the distance an object travels in a certain amount of time.

Inertia

the tendency of a body to maintain is state of rest or uniform motion unless acted upon by an external force

Kinetic Energy

energy of motion

Velocity vs Time graph

Shows the change in speed of an object over time (acceleration).

Motion

any physical movement; change in position or place

Newton's First Law of Motion (Definition)

an object at rest will stay at rest unless acted upon by an outside force; an object in motion will stay in motion unless acted upon by an outside force

Newton's First Law of Motion (Example)

when a car suddenly stops and your head continues to move foward even though your body is stopped by the seat belt

Newton's Second Law of Motion (Definition)

the greater the force applied to an object, the greater the acceleration; the smaller the mass of an object, the greater its acceleration when force is applied; only an unbalanced force can cause objects to accelerate

Newton's Second Law of Motion (Example)

the force applied to a roller coaster car in addition to the mass of the car determines the acceleration of the car; more force = more acceleration

Newton's Third Law of Motion (Definition)

for every action there is an equal and opposite reaction; forces act in pairs

Newton's Third Law of Motion (Example)

as the thrust of a rocket pushes down on Earth's surface, the rocket launches upward into the atmosphere

Potential Energy

energy stored or energy of position

reaction force

The basketball court pushes up on Kawhi Leonard's feet.

Example of work

A monkey carries a 5 kg pineapple 10 meters in 5 minutes.

Example of velocity

Nemo swims 37 m/s South to Wallaby Way in Australia.

Speed

the distance traveled by an object in a given amount of time; rate of motion; distance/time

Example of speed

Bruce swims 58 m/s

Unbalanced Force

change speed or direction of object's motion; not equal and opposite

Velocity

speed of an object and its direction of motion; changes when speed, direction or both changes

Example of Acceleration

Crush swims side to side as he surfs at 15 m/s on the Eastern Atlantic Current.

m=f/a

formula for mass

a=f/m

formula for acceleration