WHAT IS A FORCE? TEST REVIEW

DEFINE FORCE: A push or pull one body exerts on another Forces always come in pairs.

WHAT IS NET FORCE? Net force is a force that results from unbalanced forces acting on an object CHANGES THE MOTION OF AN OBJECT!!

ENERGY: POTENTIAL ENERGY- the energy of objects due to their position or condition or the energy an object could have. KINETIC ENERGY- energy of motion

WHAT IS ACCELERATION? The rate at which velocity changes Acceleration depends on the net force acting on the object and on the mass of the object.

VELOCITY: The speed AND direction of a moving object.

MOMENTUM: The mass of an object multiplied by its velocity. “BASHING POWER”

WHAT IS MASS? Mass is the amount of matter in an object. The measure of inertia of a body.

INERTIA IS: The property of a body that resists change in velocity.

FRICTION: The force that opposes motion between two surfaces that are touching each other. Air resistance- the force of air against a moving object also called drag.

NEWTONS LAWS: Newton’s First Law of Motion: OR the Law of Inertia this law states: an object at rest tends to stay at rest and an object in motion tends to stay in motion unless acted upon by an outside force. Newton’s Second Law of Motion: states the relationship of pushes, pulls, mass, and acceleration this law says: the acceleration of an object depends on the net force acting on the object and the mass of the object

NEWTON’S LAWS CONTINUTED Newton’s Third Law: this law states: whenever an object exerts a force on a second object, the second object exerts an equal and opposite force on the first object. OR for every action there is an equal and opposite reaction

APPLYING NEWTON’S LAWS First Law The amount of inertia present in a lump of matter depends partly on size and what the material is made of. A baseball has more mass than a foam ball of the same diameter, and a steel ball the size of a baseball has more mass than both balls. the more massive the object the more inertia it has.

APPLYING NEWTON’S LAWS The Second Law: if the mass of an object does not change the acceleration of the object will increase when a larger force is applied. If the same amount of force is exerted on the objects, then the acceleration of the larger mass will be less. Dealing with momentum: As your velocity increases your momentum increases, therefore you have more “Bashing Power”.

APPLYING NEWTON’S LAWS The Third Law: forces always come in pairs, an action and a reaction. Examples: The force of a climber on a rope (down), and the force of the rope on the climber (up). (pg. 75) The force of the water pump on water (forward), and the force expelled on the hose (backward). AS LONG AS THE FORCES ARE BALANCED, AND THE NET FORCE OF THE OBJECT IS ZERO, THEN THE OBJECT DOES NOT MOVE.

REVIEW: Know: Acceleration, energy, force, momentum, velocity and mass Newton’s Three Laws How to apply Newton’s Three Laws STUDY, STUDY, STUDY!!! Then you should be prepared for your test.