Exam 9: Momentum

A 51 g steel ball is released from rest and falls vertically onto a steel plate.The ball strikes the plate and is in contact with it for 0.5 ms.The ball rebounds elastically,and returns to its original height.The time interval for a round trip is 3.00 s.In this situation,the average force exerted on the ball during contact with the plate is closest to:

A car heading north collides at an intersection with a truck heading east.If they lock together and travel at 28 m/s at 46° north of east just after the collision,how fast was the car initially traveling? Assume that the two vehicles have the same mass.

In a collision between a light hydrogen molecule and a heavy water molecule,the momentum lost by one molecule is exactly the same as the momentum gained by the other molecule.

Three objects are moving along a straight line as shown in the figure.Taking the positive direction to be to the right,what is the total momentum of this system?

A 1200 kg ore cart is rolling at 10.8 m/s across a flat surface.A crane dumps 691 kg of ore (vertically)into the cart.How fast does the cart move after being loaded with ore? Assume that frictional forces may be neglected.

Two ice skaters of identical mass approach on parallel paths 1.6 m apart.Both are moving at 3.0 m/s.They join hands as they pass,maintaining their 1.6 m separation,and begin rotating about each other.What is their angular speed?

A shell explodes into two fragments,one 25 times heavier than the other.The momentum change of the lighter fragment is 25 times as great as the momentum change of the heavier fragment.

Calculate the impulse associated with a force of 4.5 N that lasts for 1.4 s.

-A block of mass m = 3.6 kg,moving on a frictionless surface with a speed vi = 9.3 m/s,makes a perfectly elastic collision with a block of mass M at rest.After the collision,the 3.6 kg block recoils with a speed of v_f = 2.7 m/s.In the figure,the speed of the block of mass M after the collision is closest to:

A container explodes and breaks into three fragments that fly off 120° apart from each other,with mass ratios 1: 4: 2.If the first piece flies off with a speed of 6.0 m/s,what is the speed of the other two fragments? (All fragments are in the plane. )

-An 8 g bullet is shot into a 4.0 kg block,at rest on a frictionless horizontal surface.The bullet remains lodged in the block.The block moves into a spring and compresses it by 3.7 cm.The force constant of the spring is 2500 N/m.In the figure,the initial velocity of the bullet is closest to:

A 0.24 kg blob of clay is thrown at a wall with an initial velocity of 23 m/s.If the clay comes to a stop in 91 ms,what is the average force experienced by the clay?

A rubber ball moving horizontally at 8.50 m/s hits a brick wall and bounces back with exactly the same speed but in the opposite direction.During this collision,its change in momentum is zero.

A girl of mass 55 kg throws a ball of mass 0.8 kg against a wall.The ball strikes the wall horizontally with a speed of 25 m/s,and it bounces back with this same speed.The ball is in contact with the wall 0.05 s.What is the average force exerted on the wall by the ball?

Two vehicles approach a right angle intersection and then collide.After the collision,they become entangled.If their mass ratios were 1: 4 and their respective speeds as they approached were both 13 m/s,find the magnitude and direction of the final velocity of the wreck.

You are standing on a skateboard,initially at rest.A friend throws a very heavy ball toward you.You can either catch the object or deflect the object back toward your friend (such that it moves away from you with the same speed as it was originally thrown).What should you do in order to maximize your speed on the skateboard?

In a ballistics test,a bullet traveling horizontally strikes and embeds itself in a large block that is free to move.During this process,the bullet transfers all of its momentum to the block.

Three solid,uniform flywheels,each of mass 65.0 kg and radius 1.47 m,rotate independently around a common axis.Two of the flywheels rotate in one direction at 3.83 rad/s;the other rotates in the opposite direction at 3.42 rad/s.Calculate the magnitude of the net angular momentum of the system.

When a baseball player hits a home run,the baseball receives a greater impulse from the bat than the bat does from the ball.

A uniform,solid flywheel of radius 1.4 m and mass 15 kg rotates at 2.4 rad/s.What is the magnitude of the flywheel's angular momentum?