Presentation on theme: "Newton’s Laws of Motion"— Presentation transcript:
1 Newton’s Laws of Motion Forces in MotionNewton’s Laws of Motion
2 TermsInertia~the tendency of all objects to resist any change in motionMomentum~ a property of a moving object that depends on the object’s mass and velocity
3 Newton’s First Law of Motion An object at rest remains at rest and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force.Objects at restNot movingWon’t move unless a push or pull is exerted on themObject in motionContinues forever at same speed & in same direction unless an unbalanced force acts on it.
4 Newton’s First Law of Motion Friction and Newton’s First LawFriction makes it difficult to observeFriction is an unbalanced force which changes motionInertia is related to mass1st law sometimes called the law of inertiaWhy you slide when car makes a turnMass is a measure of inertiaSmall mass → less inertiaEasier to change motion of object with a small mass
5 Newton’s Second Law of Motion The acceleration of an object depends on the mass of the object and the amount of force appliedAcceleration depends on massAcceleration decreases as mass increases when the same amount of force is appliedAcceleration depends on forceAcceleration increases as force increases when the mass is the sameExpressing it mathematicallyF=m·aA=F/m
6 Newton’s Third Law of Motion Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.Force pairs do not act on the same objectThe effect of a reaction can be difficult to seeMore examples:Rabbit hoppingBat hitting ballShuttle taking off
7 Momentum is a Property of Moving Objects More momentum ~ harder it is to stop or change its directionMomentum is ConservedAny time 2 or more objects interact, they may exchange momentum, but the total amount of momentum stays the sameMomentum before collision = momentum after collisionConservation of momentum & Newton’s third lawBecause action & reaction forces are equal and opposite, momentum is conserved