Exam 9: Linear Momentum and Collisions

A 3.0-kg mass is located at (0.0 m,8.0 m),and a 1.0-kg mass is located at (12 m,0.0 m).You want to add a 4.0-kg mass so that the center of mass (or center of gravity)of the three-mass system will be at the origin.What should be the coordinates of the 4.0-kg mass?

In a police ballistics test,a 2.00-g bullet suddenly hits and becomes embedded in a 5.00-kg wood block which is hanging from a 1.20-m long string.This causes the block to swing through an arc of 3.50°.What was the speed of the bullet just before it hit the block?

A car heading north suddenly collides at an intersection with a truck of the same mass heading east.If they lock together and travel at At 15° north of east just after the collision,how fast was the car initially traveling?

Three small masses are positioned as follows: 2.0 kg at (0.0 m,0.0 m),2.0 kg at (2.0 m,0.0 m),and 4.0 kg at (2.0 m,1.0 m).Determine the coordinates of the center of mass (or center of gravity)of this system.

A 1000-kg whale swims horizontally to the right at a speed of 6.0 m/s.It suddenly collides directly with a stationary seal of mass 200 kg.The seal grabs onto the whale and holds fast.What is the momentum of these two sea creatures just after their collision? You can neglect any drag effects of the water during the collision.

A 2.0-kg ball moving eastward at 3.0 m/s suddenly collides with and sticks to a 4.0-kg ball moving northward at 2.0 m/s.What is the magnitude of the momentum of this system just after the collision?

As shown in the figure,a bullet of mass 0.010 kg moving horizontally suddenly strikes a block of wood of mass 1.5 kg that is suspended as a pendulum.The bullet lodges in the wood,and together they swing upward a vertical distance of 0.40 m.The length of the string is 2.0 m.What was the speed of the bullet just before it struck the wooden block?

A 328-kg car moving at 19.1 m/s in the +x direction hits from behind a second car moving at 13.0 M/S. In the same direction.If the second car has a mass of 790kg. And a speed of 15.1 m/s. Right after the collision,what is the velocity of the first car after this sudden collision?

Three masses are located in the x-y plane as follows: a mass of 6 kg is at (0 m,0 m),a mass of 4 kg is at (3 m,0 m),and a mass of 2 kg is at (0 m,3 m).Where is the center of mass (or center of gravity)of the system?

A 900-kg car traveling 30.0° south of east at 12.0 m/s suddenly collides with a 750-kg car traveling north at 17.0 m/s.The cars stick together after colliding.What is the speed of the wreckage just after the collision?

As shown in the figure,a 60-cm length of uniform wire,of mass 60 g,is bent into a right triangle.What are the x and y coordinates of the center of mass (or center of gravity)of this triangle?

A small car meshes with a large truck in a head-on collision.Which of the following statements concerning the momentum during the collision are correct? (There could be more than one correct choice. )

A very elastic rubber ball is dropped from a certain height and hits the floor with a downward speed v.Since it is so elastic,the ball bounces back with the same speed v going upward.Which of the following statements about the bounce are correct? (There could be more than one correct choice. )

A 1500-kg car traveling at 90 km/h toward the east suddenly collides with a 3000-kg car traveling at 60 km/h toward the south.The two cars stick together after the collision.What is the speed of the cars after collision?

A very small 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 0.50 ms.The ball rebounds elastically and returns to its original height.The total time interval for a round trip is 3.00 s.What is the magnitude of the average force exerted on the ball by the plate during contact with the plate?

A 900-kg car traveling east at 15.0 m/s suddenly collides with a 750-kg car traveling north at 20.0 m/s.The cars stick together after the collision.In what direction does the wreckage move just after the collision?

Two dogs,Rover and Fido,run on a level frictionless surface.Rover runs eastward with a momentum of 24 kg .m/s,and Fido runs northward with momentum 10 kg .m/s.They make a sudden perfectly inelastic collision.What is the magnitude of their combined momentum after the collision?

A 0.140-kg baseball is thrown with a velocity of 27.1 m/s. It is struck by the bat with an average force of 5000 N,which results in a velocity of 37.0 m/s in the opposite direction from the original velocity.How long were the bat and ball in contact?

The center of mass (or center of gravity)of a two-particle system is at the origin.One particle is located at (3.0 m,0.0 m)and has a mass of 2.0 kg.The other particle has a mass of 3.0 kg.What is the location of the 3.0-kg particle?

An 8.0-g bullet is suddenly shot into a 4.0-kg block that is at rest on a frictionless horizontal surface,as shown in the figure.The bullet remains lodged in the block.The block then moves against a spring and compresses it by 3.7 cm.The force constant (spring constant)of the spring is What was the initial speed v of the bullet?