NEWTONS FIRST LAW OF MOTION INERTIA Friction a

NEWTON’S FIRST LAW OF MOTION- INERTIA Friction – a force made when two object touch other - Friction is a force that acts against the motion of one object past another each

Inertia is the ability of an object to resist changes to its motion - Is it easier to push a big person or a little person? - Inertia depends on an objects mass - The more mass an object has the greater inertia the object has

Newton’s Law of Inertia: 1. An object in motion tends to stay in motion unless acted on by an outside force 2. An object at rest tends to stay at rest unless acted on by an outside force

Measuring Inertia Mass is the measure of matter in an object -Mass is measured in Kg Weight is the pull of gravity on an object -Weight is measured in Newtons 1 kg of Mass = 10 Newtons of weight

Cool Videos Displaying Inertia http: //www. youtube. com/watch? v=_SVJMeo. HGug &NR=1 http: //www. youtube. com/watch? v=8 zs. E 3 mp. Z 6 Hw &feature=related

Newton’s 2 nd Law F = ma F means force (in N) m means mass (in Kg) a means acceleration (in meters/seconds x seconds) - the acceleration of gravity is 10 m/s 2 http: //www. youtube. com/watch? v=_XJc. ZKo. L 9 o&feature=related

Calculation Force due to Gravity If the acceleration of gravity for all things is 10 m/s 2 regardless of their mass then how do we calculate the force we feel when holding an object against gravity’s pull If a person has a mass of 100 Kg what is the force of gravity on that person? F=ma F=100 Kg x 10 m/s 2

Newton’s Third Law For every action there is an equal and opposite reaction. Is this true for objects that are not moving? -Hint: Think about the vectors that were drawing to describe the force of gravity on nonmoving objects - Door test