Text of Newtonâ€™s Laws of Motion. Learning Objectives ï‚§ State...
Newtons Laws of Motion
Learning Objectives State Newtons first law of motion. State Newtons second law of motion. State Newtons third law of motion.
Warm up 10/30 Define these words inertia
Isaac Newton If a horse draws a stone tied to a rope, the horse (if I may so say) will be equally drawn back towards the stone.... Sir Isaac Newton
Newtons First Law of Motion An object at rest will remain at rest unless acted upon by a nonzero net force an object moving at a constant velocity will continue moving at a constant velocity unless acted upon by a nonzero net force. Inertia: resistance to change in motion At rest Constant motion in a straight line AND
Inertia Depends on Mass The greater the mass of an object, the greater its inertia and the greater the force required to change its motion. 2 13
Newtons Second Law of Motion An objects acceleration depends on its mass and on the net force acting on it. Si Unit: Newtons (N)
Newtons Second Law of Motion The sleds acceleration will increase if: OR more dogs are added to increase the force. passengers are removed to decrease the mass.
Newtons Second Law of Motion Practice: What is the net force on a 1,200-kg race car accelerating at a rate of 3 m/s 2 ? 3,600 N
Newtons Third Law of Motion If one object exerts a force on another object, then the second object exerts a force of equal strength in the opposite direction on the first object. For every action, there is an equal and opposite reaction. Action Reaction
Action-Reaction Forces Force on ball Force on hands
Laws of Motion in Action 1. Use one of Newtons laws to explain why the driver was thrown forward when she braked. Newtons first law says that objects in motion stay in motion. The car stopped, but the drivers inertia kept her moving forward.
Laws of Motion in Action 2. Use one of Newtons laws to explain how the seat belt stopped the drivers body from moving too far forward. Newtons third law says that for every action force, there is an equal and opposite reaction force. The drivers body exerted an action force on the seat belt. The seat belt exerted a reaction force on the driver that stopped her motion.
Laws of Motion in Action 3. Use one of Newtons laws to determine how much force the driver will need to exert to make it to her appointment on time. Newtons second law is represented by the formula F = ma. F = (1,100 kg)(2 m/s 2 ) F = 2,200 N
Patterns in Newtons Laws Q: What pattern of motion identifies with the law of inertia? A: objects resist a change in their motion Q: What pattern exists in the law of force and acceleration? A: as force increases, so does acceleration if the mass is constant A: as acceleration increases so does force if the mass is constant A: As mass increases, acceleration decreases if the force is constant A: As mass decreases, acceleration increase if the force is constant
Patterns in Newtons Laws Q: What pattern exists in the law of action-reaction? A: Every action force has a corresponding reaction force Q: What are the action- reaction forces? A: Whenever one object exerts a force on a second object, the second object exerts an EQUAL and OPPOSITE force on the first object.