Presentation Transcript

1. Newton’s Laws

2. Newton’s Third Law Newton’s Third Law – for every action (force) there exists an equal and opposite reaction (force). http://www.youtube.com/watch?v=wUG2jbRxYoQ Newton’s Third Law ****Forces always exist in pairs that are equal. Note: this does not mean that the net force = 0.
3. A hockey stick hits a puck on the ice. Identify an action-reaction pair, and compare the forces exerted by each object. The stick exerts a force on the puck; the puck exerts a force on the stick. The stick exerts a force on the puck; the puck exerts a force on the ice. The puck exerts a force on the stick; the stick exerts a force on the ice. The stick exerts a force on the ice; the ice exerts a force on the puck.
4. What is the force pair that exists during the shuttle launch? The shuttle exerts a an upward force on the fuel; the fuel exerts an upward force on the shuttle. The shuttle exerts a downward force on the fuel; the fuel exerts an upward force on the shuttle. The fuel exerts an upward force on the shuttle and the shuttle accelerates upwards.
5. Newton’s Law of Universal Gravitation Gravitational force is directly proportional to the masses of the objects and inversely proportional to the distance between the objects.
6. Newton’s Law of Universal Gravitation G = Newton’s Gravitational Constant 6.673 x 10-11 Nm2/kg2 r = distance between objects in meters m1 and m2 = mass of objects (kg)