Physics Final 8th Grade

I hate this class.

Normal Force. What exerts it?

Normal Force. What exerts it?

Support force exerts against an object that is in contact with a stable force

Wall, ground, table

Gravity

A force that pulls an object towards another

Friction. Where is it exerted?

A force that opposes motion between two objects that are in contact

Friction is exerted in the opposite direction

Applied Force

When someone or something applies force against an object.

Balanced Forces

Equal forces act on an object in an opposite direction

Unbalanced Forces

A force causes a change in motion in an object

Unit for Force

Newtons

Forces In Same Direction

Add

Forces In Different Directions

Subtract

Vectors

Have magnitude and direction

Newton's Laws of Motion

• 1st law (Law of inertia): An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

• 2nd law: F=ma

• 3rd law: For every action there is an equal and opposite reaction

All things fall with what acceleration

9.8m/s^2

Unit For force

Newtons

Unit For Velocity/Speed

m/s

Unit For Position/Displacement/Distance

Meters

Acceleration

m/s²

Energy

Joule (J)

Mass

Gram (g)

Newton's Law of Gravitation

Every particle attracts every other particle in the universe with a force that is proportional

What is weight and how does it change on different planets

Objects weight depends on its mass and how much gravity pulls it. Different planets have different gravity so weight changes

Electric Force

A repulsive or attractive interaction between any two charged bodies

Protons Have What Type of Charge

Positive Charge

Electrons Have What Type of Charge

Negative Charge

What do opposite and same charges do

Opposite charges attract, Same charges repel each other

Why does a balloon stick to the wall after you rub it on your head

adding a surplus of electrons

What is magnetic force?

A result of the electromagnetic force

Every magnet has what?

Every magnet has a south and north pole

What is energy?

The force that causes things to move

unit for energy

Joules

What is potential energy?

The energy that is stored in an object

What is kinetic energy?

The energy of motion

Law of Conservation of Energy

Energy cannot be created or destroyed

Formula for kinetic energy

KE = ½mv²

Formula for potential energy

PE= mgh (mass)(9.8 N/kg)(height in m)