Practice Problems Conservation of Momentum

Directions: On this worksheet you will be practicing your knowledge of conservation of momentum.

 Question 1  A 2.5-kg ball has a KE of 82 J. What is the ball's momentum? omit10.1 kg m/sec18.1 kg m/sec164 kg m/sec20.2 kg m/sec
 Question 2  A 81-kilogram skater at rest on a frictionless rink throws a 2.5-kilogram ball, giving the ball a velocity of 8.1 m/s. Which value describes the skater's subsequent motion? -25 m/secomit-0.25 m/sec-5.25 m/sec-0.04 m/sec
 Question 3  A 6060-kg freight car moving at 8.1 m/sec collides and couples with an 15150-kg freight car which is initially at rest. The approximate common final speed of these two cars is 28.35 m/sec5.79 m/sec3.24 m/secomit11.34 m/sec2.31 m/sec
 Question 4  A 8.1-g bullet moving at 300 m/sec is brought to a stop in 0.8 seconds when it strikes a tree. The average braking force exerted on the bullet by the tree is there is not enough information to calculate the force-750 Nomit-1.94 N-3.04 N
 Question 5  You push two objects, both initially at rest, with the same amount of force through the same distance. Object A has mass, m, while object B has mass, 16m. omitA will gain 4 times as much momentum as BA will gain 4 times as much KE as BB will gain 4 times as much momentum as AB will gain 4 times as much KE as A
 Question 6  A heavy and a light object are released from the same height and fall to the ground. Just before they strike the ground, they will have none of the other choices are trueexperienced the same forceomitgained the same amount of momentumgained the same kinetic energy
 Question 7  A girl jumps upward from the surface of the earth. Does an external force act on system 'girl + earth'? yes, because each participant (girl and earth) will accelerateomitno, the each participant (girl and earth) experience equal but opposite impulses and equivalent changes in momentumno, all forces in the diagram cancel each other and neither participant (girl and earth) is acceleratedyes, because each participant (girl and earth) will experience a change in its momentum
 Question 8  Running at 4.05 m/sec Jack, a 45-kg quarterback, collides with Leon, a 90-kg tackle, who is traveling towards him at 8.1 m/sec. Upon colliding, Leon continues to travel forward towards Jack, at 1.62 m/sec. How fast does Jack leave the collision? 1.62 m/sec-8.91 m/sec-3.24 m/sec17.01 m/secomit
 Question 9  In which picture does Bronco have the greatest terminal velocity? omit