Exam 6: Linear Momentum and Collisions

A Ping-Pong ball moving East at a speed of 4 m/s collides with a stationary bowling ball. The Ping-Pong ball bounces back to the West, and the bowling ball moves very slowly to the East. Which object experiences the greater magnitude impulse during the collision?

A small bomb, of mass 10. kg, is moving toward the North with a velocity of 5.0 m/s. It explodes into three fragments: a 5.0 kg fragment moving West with a speed of 8.0 m/s; a 4.0 kg fragment moving East with a speed of 10. m/s; and a third fragment with a mass of 1.0 kg. What is the velocity of the third fragment? (Neglect air friction.)

A 2000. kg car, traveling to the right at 30. m/s, collides with a brick wall and comes to rest in 0.20 s. The average force the car exerts on the wall is

Two cars suffer a head-on collision. What is conserved in the collision?

Two astronauts, with masses 60. and 80. kg, are initially at rest in outer space. They push each other apart. How far has the heavier astronaut moved when the lighter astronaut has moved 12. m?

Suppose a bug spatters upon your windshield as you drive down the road. Which sustains the greater change of momentum?

In space, a 4.0 kg metal ball moving 30. m/s has a head-on collision with a stationary second ball of equal mass. After the elastic collision, what are the velocities of the balls?

Momentum is conserved during a completely inelastic collision.

A right isosceles triangle is cut out from a piece of sheet metal. The two equal sides are 1.0 m long each. How far is the center of gravity from the right angle (90. °) vertex of the triangle?

Define linear momentum.

Which of the following has units of momentum?

A mine railroad car, of mass 200 kg, rolls with negligible friction on a horizontal track with a speed of 10.0 m/s. A 70. kg stunt man drops straight down a distance of 4.0 m, and lands in the car. How fast will the car be moving after this happens?

Momentum of a system isn't always constant. What condition assures that momentum is conserved for a system?

In a game of pool, the white cue ball hits the 5 ball and stops, while the 5 ball moves away with the same velocity as the cue ball had originally. The type of collision is

An empty coal-car (mass 20,000.kg) of a train coasts along at 10.m/s. An unfortunate 3000. kg elephant falls from a bridge and drops vertically into the car. Determine the speed of the car immediately after the elephant is added to its contents.

A rope is towing a 100-kg rock, from rest, with a force that varies with time, as shown in Figure 6-4. Figure 6-4 At the end of 8.0 s, the velocity of the rock is

A 3 kg mass is positioned at (0, 8), and a 1 kg mass is positioned at (12, 0). What are the coordinates of a 4 kg mass which will result in the center of mass of the system of three masses being located at the origin (0, 0)?

1.0 kg is at ( -2.0, 2.0); 2.0 kg is at ( 2.0, -4.0); and 3.0 kg is at ( 2.0, 0.0). (a) What is the x coordinate of the center of mass? (b) What is the y coordinate of the center of mass?

A bullet of mass 20. g, traveling at 350. m/s, strikes a steel plate at an angle of 30.° with the plane of the plate. It ricochets off at the same angle, at a speed of 320. m/s, as shown in Figure 6-3. What is the magnitude of the impulse that the wall gives to the bullet? Figure 6-3

Figure 6-1, an Olympic diver dives off the high-diving platform. -See Figure 6-1. The area under the curve on a F - t graph represents