Apr 16 / 17 Act E 80 Newton’s Laws of Motion LEARNING TARGET: I can explain the relationship between force and motion as stated in all of Newton’s 3 Laws of Motion. CH Q What relationships (3) between force and motion did Newton discover? VOCAB: next slide

Balanced forces Unbalanced forces Friction net force two forces acting in opposite directions on an object, and equal in size. Balanced forces Unbalanced forces Friction net force two forces acting on an object are not equal in size, causing a change in motion. the resistance that one surface or object encounters when moving over another. the sum of all the forces acting on an object.

PROCEDURE AND DATA MATERIALS: PROCEDURE: Read on pg. E 29-35 Stop and Think 1-5 in journals DATA: WS 80.1 Anticipation Guide: Newton’s Laws of Motion

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Newton’s 3 Laws of Motion POST DISCUSSION Newton’s 3 Laws of Motion

Newton’s 1st Law of Motion 1st Law (also known as the Law of Inertia):   An object at rest will stay at rest – an object in motion will continue with that motion (direction and speed) until an outside force acts on it.

Newton’s 2nd Law of Motion   An object’s force is related to its mass and acceleration ( F = m x a ).

Let’s Practice Remember  F=ma 500 N engine accelerates a 500 kg car. What is the car’s acceleration? Force = mass x acceleration 500 N = 500 kg x a a = 500 N / 500 kg a = 1 m/s2 500 N engine accelerates a car by 0.5 m/s2. What is the mass of the car? K  f = 500N a = 0.5 m/s2 U m =? F  F = m x a P  m = 500 N / 0.5 m/s2 A  m = 1000 kg m = F a

One More! What is the minimum force required to get a 10,000Kg space shuttle off the ground? Hint: acceleration  gravity  9.8 m/s2 K  m=10,000 Kg a= 9.8 m/s2 U f=? F  F = m x a P  F = 10,000 kg x 9.8 m/s2 A  F = 98,000 N

Newton’s  N = Kg m/s/s OR N = Kg m/s2 One newton is equal to 1 kilogram meter per second squared. In plain English, 1 newton of force is the force required to accelerate an object with a mass of 1 kilogram 1 meter per second per second. N = Kg m/s/s OR N = Kg m/s2 The force that will give a mass of 1 kilogram an acceleration of 1 meter per second per second.

Newton’s 3rd Law of Motion   For every action there is an equal and opposite reaction.

Discuss ALL 3 of Newton’s Laws using a hockey game as an example. The hockey puck stays at rest until a force is placed on it by a player and hits it, then it stays in motion until another force stops it or changes its direction, like another player or the net when it scores. The greater the force hit on the puck, the greater the acceleration If 2 hockey players are fighting and push off each other, they will both accelerate away from each other at the same speed, depending on their masses. The heavier (the more mass) then the less acceleration (less speed).

ANALYSIS - Discuss and answer Q 2-4 on pg. E 36 ANS CH Q What relationships (3) between force and motion did Newton discover? A: An object will keep doing what it is doing until an outside force changes it. (1st Law of Inertia) Force is equal to an objects mass multiplied times it’s acceleration. F=ma (2nd Law) For every action there is an opposite and equal reaction (3rd Law) HOMEWORK Journal / vocab