Vince Formica Tom Dougherty Richard Saylor

 Momentum= mass * velocity ◦ The symbol for the quantity of momentum is ‘p’  Therefore p= m * v  Momentum is a vector quantity ◦ Units for momentum are kg*m/s

 Impulse= Change in momentum ◦ Impulse= F* t ◦ Change in Momentum= m( v)  So.. F* t= m( v)  Another symbol for Impulse is J ◦ J= p ◦ Unit for impulse is Ns

 Derived from Newton’s second law Equation ◦ F=m * a a=m * ( v/t)  F= m * ( v/t)  ** F * t= m * v

 For a collision occurring between two objects, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision.  Momentum is not lost, it is transferred in an isolated system  Therefore:

 Since the forces that act upon each other are of equal magnitude, the time of the collision must be the same for the two objects  Since the forces and the time are equal, this created an impulse of equal magnitude in an opposite direction

 Therefore, since we know that impulse is equal to the change in momentum, it is logical to say that the two objects also experience equal and opposite momentum changes  *In an isolated system, the total momentum is still equal, however, the momentum lost by one object is gained by the other

 M 1 V 1i + M 2 V 2i = M 1 V 1f + M 2 V 2f ◦ M 1 = mass of object 1 ◦ V 1i = initial velocity of object 1 ◦ M 2 = mass of object 2 ◦ V 2i = initial velocity of object 2 ◦ V 1f = final velocity of object 1 ◦ V 2f = final velocity of object 2

 X com = M 1 X 1 + M 2 X 2 M 1 + M 2 X com = position of the center of mass M 1 = mass of object 1 X 1 = 0 M 2 = mass of object 2 X 2 = distance between center points

 1. While driving down the road, a firefly strikes the windshield of a bus and makes a quite obvious mess in front of the face of the driver. This is a clear case of Newton's third law of motion. The firefly hit the bus and the bus hits the firefly. Which of the two forces is greater: the force on the firefly or the force on the bus?  2. Many people are familiar with the fact that a rifle recoils when fired. This recoil is the result of action-reaction force pairs. A gunpowder explosion creates hot gases which expand outward allowing the rifle to push forward on the bullet. Consistent with Newton's third law of motion, the bullet pushes backwards upon the rifle. The acceleration of the recoiling rifle is...  a. greater than the acceleration of the bullet.  b. smaller than the acceleration of the bullet.  c. the same size as the acceleration of the bullet.

 1. A large truck and a Volkswagen have a head-on collision. ◦ a. Which vehicle experiences the greatest force of impact? ◦ b. Which vehicle experiences the greatest impulse? ◦ c. Which vehicle experiences the greatest momentum change? ◦ d. Which vehicle experiences the greatest acceleration? ◦ 2.

 Isolated System: Yes or No?  1. Two cars collide on a gravel roadway on which frictional forces are large.  2. Hans Full is doing the annual vacuuming. Hans is pushing the Hoover vacuum cleaner across the living room carpet.  3. Two air track gliders collide on a friction- free air track