BATTEN BARR NEWTON'S LAWS OF MOTION

FORCE A push or a pull SI unit is newtons (N) 1 newton = the amount of force it takes to lift a quarter- pound hamburger Changes an objects motion

FORCES Balanced Forces – when the effects of two or more forces cancel each other Unbalanced Forces – when the effects of the forces do not cancel each other The combination of the forces is the net force.

NEWTON’S 1 ST LAW An object in motion stays in motion and an object at rest stays at rest Unless acted on by an unbalanced force! Outside forces include A push or a pull Running into something Friction

Friction is a force between 2 surfaces in contact that resists the motion This causes moving objects to slow down. Acts in the direction opposite the motion. Inertia is the tendency to resist a change in motion The more mass – the more inertia

NEWTON'S 2 ND LAW A change in motion occurs only if a net forces is exerted on an object The acceleration is in the direction of the net force. Net Force= Mass x Acceleration The more mass of an object = more force needed to accelerate the object. Which cart needs more force to accelerate?

NEWTON’S 3 RD LAW For every action, there is an equal and opposite reaction. Force exerted by the first object is the action force Force exerted by the second object is the reaction force. Example: a swimmer pushing off a wall Swimmer exerts the action force The wall exerts the reaction force.

KEPLER’S 3 LAWS 1 st law - sometimes referred to as the law of ellipses - explains that planets are orbiting the sun in a path described as an ellipse 2 nd law - sometimes referred to as the law of equal areas - describes the speed at which any given planet will move while orbiting the sun. 3 rd law - sometimes referred to as the law of harmonies - compares the orbital period and radius of orbit of a planet to those of other planets

Newton was able to show that his laws of gravitation gave the same results as Kepler's. In fact, Newton was able to take things farther with his strong math background to show that the shape of the orbits were conic sections (for those of you that have seen that stuff in math).the shape of the orbits

MACHINES What is a machine? a device that makes work easier Simple machine – uses one movement List/draw the types of simple machines Compound machine - combination of simple machines

MECHANICAL ADVANTAGE Number of times a machine increases the force applied to it Output force (F o ) Input force (F i ) MA = F o / F i MA = 1 good MA > 1 really good