Chapter 12 Mr Hodesblatt

Newtons’s laws Every change you feel is caused by a force Many of these were first laid out by Sir Issac Newton in his laws of motion They apply to almost everything we can perceive and see

Newton’s First law An object at rest stays at rest and an object in motion maintains its velocity unless it experiences a net force Objects change their state of motion only when a net force is applied Eg book sliding on a carpet will stop Objects tend to maintain their state of motion Friction will cause an object to stop after a time

Inertia In short-Matter resists any change in motion Inertia-tendency of an object to resist a change in motion unless an outside force acts on the object All objects resist some changes in motion, so every object has some inertia In short-Matter resists any change in motion

Inertia A common example of inertia is observed in cars What happens when a car turns? You slide to the side What happens when a car stops? You continue to move Why? Your body wants to continue moving even though the car has stopped or moved Seat belts help to stop this by adding an unbalanced force in order to balance out the force keeping you going forward.

Newton’s 2nd law These forces acting on a object that we have been discussing thus far can be quantified 2nd law describes the effect of unbalanced forces on an object Net Force=Mass X Acceleration Greater mass means an object accelerates less A greater mass will have more force even moving at the same speed of an object moving at the same speed Force is measured in newtons

F=MA M= 175 kg a=.657 m/s^2. F?