Presentation on theme: "Newton’s Laws of Motion"— Presentation transcript:
1 Newton’s Laws of Motion Chapter 4 Sections 1, 2, and 3Glencoe: Pages
2 Newton’s 1st LawAn object at rest will remain at rest, and an object in motion will remain in motion unless acted on by an outside forceInertia – the tendency of an object to continue its current state of motion, at rest or motionExample: pulling a tablecloth outfrom under the table setting, or a car running into a wall
3 Newton’s 1st LawIf the car were to abruptly stop and the seat belts were not being worn, then the passengers in motion would continue in motion. The passengers would likely be propelled from the car and be hurled into the air becomes projectiles and continue in projectile-like motion.
4 Newton’s 1st LawIn this example, the ladder continues in motion because no outside force changes its original motion, until the ladder hits the ground.
5 Newton’s 2nd LawThe unbalanced force acting on an object equals the object’s mass times the object’s acceleration F = m•aSI units for force = Newton***(1 N = 1 kg·m/s2)***
6 Newton’s 2nd LawIt is obviously takes less force to make the ball accelerate because the ball has less mass.
7 Newton’s 2nd LawExample: Think of the force required to push an empty shopping cart, and the force required to push a full shopping cart. What is the difference?More force applied = greater acceleration
8 Newton’s 2nd Law Weight ≠ Mass Weight – the measure of gravity pulling on an objectMass – the measure of the amount of matterin an object
9 Newton’s 2nd Law Weight influences shape On land a supporting skeleton is required In water less body support required because the water helps lift the mass*Animals can be larger if they live in the water
10 Newton’s 2nd LawFree fall – motion of a body when the only force acting on it is gravityTerminal velocity – maximum velocity reached when air resistance pushes up as much as gravity pulls down Force of gravity pulling down = force of air resistance pushing up
11 Newton’s 3rd LawFor every action there is an equal but opposite reaction***Action and reaction forces are applied to different objects These forces occur in pairs at the same time, but do not cancel out!Example: rocketry