Transcript Document
Newton’s Laws of Motion (chapter 4) Newton’s 1st Law of Motion • An object at rest will remain there unless a force acts on it; likewise, a moving object will continue forever unless a force slows it. • Or…unbalanced forces cause motion Inertia and Mass • Inertia is the tendency of an object to resistant a change in motion • The more mass… • …the more inertia! Law of Inertia and the 1st Law Newton’s 2nd Law of Motion • Force = mass x acceleration • Acc = Force/mass • Mass = Force/acc • Force and mass are directly related • Force and acc are directly related • Mass and acc are indirectly related • And finally, the label for force is the Newton. • Newtons = (kg)(m/s2) Gravity • Definition – an attractive force between any 2 objects • One of the 4 basic forces • Law of Universal Gravitation • Allows you to calculate the actual force between 2 objects Earth’s gravitational acceleration • Force = mass x gravitational acceleration • F = m g (this is also known as the weight of the object) • g = 9.8 m/s2 • http://www.factmonster.com/ipka/A0875450.html Projectile motion Centripetal force • A force directed toward the center of curved path • Centripetal acceleration is directed toward the center of a curved path Newton’s 3rd Law of Motion • “for every action, there’s an equal and opposite reaction” Momentum = mass x velocity = kg m/s • Law of Conservation of Momentum • Momentum never changes!