2 The Third Law of MotionFor every action force, there is an equal and opposite reaction forceJumping on a trampoline cause the trampoline to exert an equal force upwardThe forces will always be equal but in opposite directions
3 The Third Law of MotionAction and Reaction forces do not cancel each other outThis is because the force is equal but the force is being applied to different objects
4 Rocket PropulsionIn aerospace engineering, the principal of action and reaction is very important.Newton's third law explains the generation of thrust by a rocket engineHot exhaust gas is produced through the combustion of a fuelThe hot exhaust gas flows through the rocket nozzle and is accelerated to the rear of the rocketIn re-action, a thrusting force is produced on the engine mount.
5 Momentum A moving object has a property called momentum Momentum will have the direction of the velocityMomentum can be positive or negativeMomentum = mass (kg) x velocity (m/s)p = m x v
6 What is the momentum of a car with a mass of 1300 kg traveling at a speed of 28 m/s?
7 A baseball thrown by a pitcher has a momentum of 6. 0 kg m/s A baseball thrown by a pitcher has a momentum of 6.0 kg m/s. If the baseball’s mass is 0.15 kg, what is the baseball’s speed?
8 What is the mass of a person walking at a speed of 0 What is the mass of a person walking at a speed of 0.8 m/s if their momentum is 52 kg m/s?
9 Law of Conservation of Momentum The momentum of an object doesn’t change unless its mass, velocity or both changeThe total momentum of all objects in a collision will be the same before and after the collisionTotal momentum can’t be lost or created.Law of conservation of momentumIf a group of objects exerts forces only on each other, their total momentum shouldn’t change.