Exam 8: Momentum,impulse,and Collisions

During a collision with a wall,the velocity of a 0.200-kg ball changes from toward the wall to 12.0 m/s away from the wall.If the time the ball was in contact with the wall was 60.0 ms,what was the magnitude of the average force applied to the ball?

An 8.0-g bullet is shot into a 4.0-kg block,at rest on a frictionless horizontal surface (see the figure).The bullet remains lodged in the block.The block moves into an ideal massless spring and compresses it by 8.7 cm.The spring constant of the spring is 2400 N/m.The initial velocity of the bullet is closest to

A block of mass m = 8.40 kg,moving on a horizontal frictionless surface with a speed 4.20 m/s,makes a perfectly elastic collision with a block of mass M at rest.After the collision,the 8.40 block recoils with a speed of 0.400 m/s.In the figure,the blocks are in contact for 0.200 s.The magnitude of the average force on the 8.40-kg block,while the two blocks are in contact,is closest to

Two ice skaters push off against one another starting from a stationary position.The 45.0-kg skater acquires a speed of 0.375 m/s.What speed does the 60.0-kg skater acquire? Assume that any other unbalanced forces during the collision are negligible.

A 480-kg car moving at 14.4 m/s hits from behind a 570-kg car moving at 13.3 m/s in the same direction.If the new speed of the heavier car is 14.0 m/s,what is the speed of the lighter car after the collision,assuming that any unbalanced forces on the system are negligibly small?

A car of mass 1689 kg collides head-on with a parked truck of mass 2000 kg.Spring mounted bumpers ensure that the collision is essentially elastic.If the velocity of the truck is (in the same direction as the car's initial velocity)after the collision,what was the initial speed of the car?

A billiard ball traveling at 3.00 m/s collides perfectly elastically with an identical billiard ball initially at rest on the level table.The initially moving billiard ball deflects 30.0° from its original direction.What is the speed of the initially stationary billiard ball after the collision?

A 620-g object traveling at 2.1 m/s collides head-on with a 320-g object traveling in the opposite direction at 3.8 m/s.If the collision is perfectly elastic,what is the change in the kinetic energy of the 620-g object?

A 2.50-kg stone is dropped from rest at a height of 3.75 m.What impulse does gravity impart to this stone from the instant it is dropped until it hits the ground,assuming negligible air resistance?

A small glider is coasting horizontally when suddenly a very heavy piece of cargo falls out of the bottom of the plane.You can neglect air resistance.Just after the cargo has fallen out

A 10.0-kg shell is traveling horizontally to the right at 25.0 m/s relative to the ground when it explodes into two fragments,one of mass 3.00 kg and the other of mass 7.00 kg.The lighter fragment goes directly forward,and the explosion releases 1.50 × 10³ J of mechanical energy to the fragments.Find the magnitude and direction of the velocity of the heavier fragment relative to the ground just after the explosion.Ignore the effect of any ejected gases.

A time-varying horizontal force F(t)= At⁴ + Bt² acts for 0.500 s on a 12.25-kg object,starting at time .In the SI system,A has the numerical value 4.50 and B has the numerical value 8.75. (a)What are the SI units of A and B? (b)What impulse does this force impart to the object?

In a collision between two objects having unequal masses,how does magnitude of the impulse imparted to the lighter object by the heavier one compare with the magnitude of the impulse imparted to the heavier object by the lighter one?

A small car has a head-on collision with a large truck.Which of the following statements concerning the magnitude of the average force due to the collision is correct?

A 310-g air track cart is traveling at 1.25 m/s and a 260-g cart traveling in the opposite direction at 1.33 m/s.What is the speed of the center of mass of the two carts?

Two objects of the same mass move along the same line in opposite directions.The first mass is moving with speed v.The objects collide,stick together,and move with speed 0.100v in the direction of the velocity of the first mass before the collision.What was the speed of the second mass before the collision?

A 0.500-kg ball traveling horizontally on a frictionless surface approaches a very massive stone at 20.0 m/s perpendicular to wall and rebounds with 70.0% of its initial kinetic energy.What is the magnitude of the change in momentum of the stone?

A 2.00-kg object traveling east at 20.0 m/s collides with a 3.00-kg object traveling west at 10.0 m/s.After the collision,the 2.00-kg object has a velocity 5.00 m/s to the west.How much kinetic energy was lost during the collision?

A baseball is thrown vertically upward and feels no air resistance.As it is rising

There must be equal amounts of mass on both side of the center of mass of an object.