Chapter+6+Momentum

Chapter 6 Momentum and Collisions By: Mr. Dr. Prof. Jon Tanguay

Formulas: Momentum:

Impulse: Impulse-Momentum Theorum: Conservation of momentum: Inelastic collision: Elastic collision: Momentum- the product of an objects mass and velocity. Momentum is a vector quantity, the direction of the vector is the same as the direction of velocity. (units are kg*m/s) Impulse- change in momentum of a body due to a force acting upon it for a short amount of time. (units are N*s) Area under a force vs. time graph is equal to the impulse. Inelastic collision- when two objects collide and stick together. Kinetic energy is not conserved in this type of collision. Elastic collision- when two objects collide and bounce off of each other. Momentum and kinetic energy are both conserved. media type="youtube" key="XFhntPxow0U" height="315" width="420" __Multiple Choice Questions__ ** 1. If the force on an object is doubled, and the time during which the object is in contact with the force is reduced by half, the impulse would: ** A. Double   B. Increase by -3/4   C. Remain the same   D. Reach or approach zero  ** 2. If the velocity of an object is doubled, what happens to the momentum? ** A. it is tripled   B. remains the same   C. it is doubled   D. the momentum increases by a factor equal to the square root of the velocity  ** 3. In an elastic collision, which of the following are true? ** I. Kinetic energy is conserved   II.Momentum of the faster object is decreased by 3/4   III. Momentum is conserved  IV. Kinetic energy and momentum are not conserved  A. I only   B. III only   C. III and IV only   D. I and III only   E. All except IV are true  ** 4. If a 12 kg object and a 14 kg object have the same momentum, which has a greater velocity? ** A. The 12 kg object   B. The 14 kg object   C. The objects have equal momentums, therefore they have equal velocities   D. Not enough information given to determine velocity  ** 5. If the objects in question 4 collided in an inelastic collision, which object would have the greater final velocity? ** A. The 12 kg object   B. The 14 kg object   C. Not enought information is given to determine final velocity   D. The final velocities would be equal  __ Additional Questions __ 1. Zach (mass 175 kg) and Kevin (mass 160 kg) are running towards each other on the football field, Zach is moving at a constant speed of 5 m/s and Kevin is moving at 7 m/s. If they collide in a perfectly inelastic collision, what will their final velocity be?  2. Patrick hits a tennis ball of mass .3 kg and gives it a velocity of 34 m/s, what is the balls momentum?  3. What is the impulse on the ball if Patrick exerts a force of 27 N on the ball for .001 s?   4. Bobby hits a pool ball of mass 3 kg, and gives it a velocity of 5 m/s, if the ball strikes another ball of the same mass, if that ball moves off with a velocity of 4 m/s, what is the final velocity of the ball Bobby originally hit? 