Momentum Momentum Clip
Collisions Newton’s third law tells us that any time two objects hit each other, they exert equal and opposite forces on each other. The effect of the force is not always the same.
Momentum The quantity of motion an object has Takes into account mass & velocity Big objects have more momentum than smaller objects moving at the same speed Commonly used in sports “The Minnesota Vikings are showing a lot of momentum” Players have a lot of momentum Physis of football
Momentum Momentum is the mass of an object times its velocity.
Momentum Momentum = mass*velocity (or speed) Momentum symbol = P Units are kg*m/s P=m*v A school bus with a mass of 1000kg is travelling at 20m/s. What is its momentum?
Example Problem #1 An airplane with a mass of 2,000kg is travelling at 100m/s. What is the momentum?
Example Problem #2 A turkey has a momentum of 50kg*m/s, and is running 10m/s. What is its mass?
Example Problem #3 A 10kg bowling ball has a momentum of 30kg*m/s. What is its velocity?
Example Problem #4 A lion is running to catch an antelope with a velocity of 30m/s. What is the momentum if the lion has a mass of 80kg?
Example Problem #5 The momentum of a duck waddling at 0.20m/s is 4 kg*m/s. What is the duck’s mass?
Law of Conservation of Momentum Law of conservation of momentum: as long as interacting objects are not influenced by outside forces, the total amount of momentum is constant Total momentum before interaction = total momentum after interaction
Example Problem An astronaut at rest throws a 2 kg wrench away from her at a velocity of -10 m/s. If the astronaut’s mass is 100 kg, at what velocity does the astronaut move backward after throwing the wrench? Find momentum before and after p1 = p2 or m1v1 = m2v2 2*(-10) = 100*v2