#1 A rubber ball with a mass of 0.185 kg is dropped from rest. From what height was the ball dropped, if the magnitude of the ball's momentum is 0.720 kg · m/s just before it lands on the ground?

#2 A member of the volleyball team spikes the ball. During this process, she changes the velocity of the ball from 5.2 m/s to −23.3 m/s along a certain direction. If the impulse she delivers to the ball is −7.8 kg · m/s, determine the mass of the volleyball.

#3 A particle with a mass of 1.25 kg is acted on by a force Fx acting in the x-direction. If the magnitude of the force varies in time as shown in the figure below, determine the following. Impulse of the force Final velocity of the particle (assume u=0 m/s) Final velocity of the particle if u = -1.50 m/s

#4 A 0.150 kg baseball traveling with a horizontal speed of 5.90 m/s is hit by a bat and then moves with a speed of 42.2 m/s in the opposite direction. What is the change in the ball's momentum?

#5 A loaded tractor-trailer with a total mass of 4900 kg traveling at 2.8 km/h hits a loading dock and comes to a stop in 0.64 s. What is the magnitude of the average force exerted on the truck by the dock?

Total momentum remains constant Types of Collisions Elastic Collisions Inelastic Collisions Objects bounce off each other with no loss of energy (no damage or deformation is done to either object) Objects collide, but damage/deformation/sticking will occur to some extent Some of the original energy is used in compression or breaking, or is converted to sound, heat, etc. Total momentum remains constant Total kinetic energy remains constant Kinetic energy is NOT conserved Examples: atoms, magnetic bumpers bug hitting a windshield; baseball bat against baseball

A fan and a sail are mounted vertically on a cart that is initially at rest on a horizontal table as shown: When the fan is turned on an air stream is blown towards the right and is incident on the sail. The cart is free to move with negligible resistance forces. After the fan has been turned on the cart will A. move to the left and then to the right. B. remain at rest. C. move towards the right. D. move towards the left.

  #7 A professional boxer hits his opponent with a 1175-N horizontal blow that lasts 0.160 s. The opponent's total body mass is 119 kg and the blow strikes him near his center of mass and while he is motionless in midair. Determine the following. (a) impulse the boxer imparts to his opponent by this blow (b) the opponent's final velocity after the blow

#8 Two ice skaters stand facing each other at rest on a frozen pond. They push off against one another and the 48-kg skater acquires a speed of 0.62 m/s. If the other skater acquires a speed of 0.83 m/s, what is her mass?

#9 During a football game, a receiver has just caught a pass and is standing still. Before he can move, a tackler, running at a velocity of +3.9 m/s, grabs and holds onto him so that they move off together with a velocity of +2.1 m/s. If the mass of the tackler is 110 kg, determine the mass of the receiver. Assume momentum is conserved.

#10 When a golfer tees off, the head of her golf club which has a mass of 200 g is traveling 52 m/s just before it strikes a 46-g golf ball at rest on a tee. Immediately after the collision, the club head continues to travel in the same direction but at a reduced speed of 45 m/s. Neglect the mass of the club handle and determine the speed of the golf ball just after impact.

#11 A 6.00-g bullet has a muzzle velocity of 220 m/s when fired by a rifle with a weight of 40.0 N. Determine the recoil speed of the rifle. If a marksman with a weight of 700 N holds the rifle firmly against his shoulder, determine the recoil speed of the shooter and rifle.

#12 A man holding a rock sits on a sled that is sliding across a frozen lake (negligible friction) with a speed of 0.490 m/s. The total mass of the sled, man, and rock is 95.0 kg. The mass of the rock is 0.300 kg and the man can throw it with a speed of 15.5 m/s. Both speeds are relative to the ground. Determine the speed of the sled if the man throws the rock forward (i.e. in the direction the sled is moving). Determine the speed of the sled if the man throws the rock directly backward.

#13 A cue ball at rest on a frictionless pool table is hit dead center by a pool stick, giving it an impulse of +1.15 N · s. The ball slides (the combination of hitting the ball dead center and no friction allows this to happen) along the table and makes a head-on elastic collision with another pool ball. If both pool balls have a mass of 0.166 kg, determine the velocity of the second ball the instant after the collision.

Answers 0.771 m 0.27 kg A) 24 N·s .. Multiple choice A) 188 kg m/s B) 19.2 m/s C) 17.7 m/s .. Multiple choice A) 188 kg m/s 1.58 m/s 35.9 kg 94.3 kg 30.4 m/s A) 0.323 m/s 0.0175 m/s A) 0.442 m/s 0.541 m/s 6.93 m/s