Key Terms to use in assessment Forces and Motion Key Terms to use in assessment

Force Any push or pull

Inertia The tendency of an object to resist a change in motion Not wanting to start moving or not wanting to stop moving

Momentum Characteristic of a moving object relating the object’s mass and velocity The bigger and more massive the object, the more momentum it will have The faster an object moves, the more momentum it will have Momentum = mass x velocity ? = 12 kg x 10 m/s Momentum = 120 N

1st Law of Motion AKA- The law of Inertia 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

2nd Law of Motion Force = mass x acceleration Force is measured in Newtons Example- solve for force Mass = 8 kg Acceleration = 10 m/s/s Force = 8 x 10 Force = 80 N

3rd Law of Motion For every action there is an equal and opposite reaction

Friction Force produced when two surfaces rub and come in contact with each other. Heat is produced Acts in opposite direction of motion

Conservation of Energy Energy is never created nor destroyed, it only changes form

Potential Energy The stored energy of an object at rest Directly related to its mass and distance from a surface PE= mass x gravity x height Gravity is 10 m/s/s

Which has more Potential Energy? Ball on left or ball on right? (Gravitational) potential energy depends on the weight and height of the object

Kinetic Energy (KE) The energy of an object in motion KE = 0.5 x mass x velocity x velocity Example = 0.5 x 2kg x 3m/s x 3m/s = 1 x 9 = 9 J

Weight Weight = mass x gravity Example Weight = 120N Gravity = 10 m/s/s Mass = ? Mass = weight / gravity  120 / 10 = 12 kg