# Calculate the final speed of a 140 kg football player initially running

Calculate the final speed of a 140 kg football player initially running PROBLEM ONE: Calculate the final speed of a 140 kg football player initially running at a speed of 20.0 m/swho collides with a goal post and experiences a backward force of 3.5 x 104 N for 4.5 x102 seconds.PROBLEM TWO: A baseball has a mass of 0.158 kg. The magnitude of the velocity of a pitched ball is 60.0m/s and the velocity of the batted ball is 55.0 m/s in the opposite direction. If the magnitude of theaverage force applied by the bat is 8.52 *103N, for how long does the ball remains in contact with the batfor?PROBLEM THREE:In the graph below,Mass #1 = 5kgMass #2 = 7kgMass #3 = 9 kg.What is the center of mass for this system?PROBLEM FOUR:A 3 kg block (m1) moving at 2 m/s has an elastic collision with a stationary block (m2) ofmass 5 kg. Find the velocity of each block after the collision. Also show that the sum of initial kineticenergies and the sum of final kinetic energies are equal.PROBLEM FIVE:A 80 kg running back moving at 6 m/s makes a perfectly inelastic collision with a 118 kgline-backer who is initially at rest. What is the speed of players after the collision?PROBLEM SIX:A 10-g bullet moving 1 000 m/s strikes and passes through a 2.0-kg block initially at rest,as shown. The bullet emerges from the block with a speed of 400 m/s. To what maximum height will theblock rise above its initial position?PROBLEM SEVEN:A 2.4-kg ball falling vertically hits the floor with a speed of 2.5 m/s and rebounds with aspeed of 1.5 m/s. What is the magnitude of the impulse exerted on the ball by the floor?