Newton’s Laws of Motion (chapter 4)

Newton’s 1 st 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 1 st Law

Newton’s 2 nd 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/s 2 )

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/s 2

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 3 rd 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!