Physics Momentum

A container with a mass of 5 kg is lifted to a height of 8 m. How much work is done by the gravitational force?

• 400J

• -400J

• 50J

• -50J

When comparing the momentum of two moving objects, which of the following is correct?

• The object with the higher velocity will have less momentum if the masses are equal.

• The more massive object will have less momentum if its velocity is greater.

• The less massive object will have less momentum if the velocities are the same.

• The more massive object will have less momentum if the velocities are the same.

Andrew is driving his 2000 kg car at 50 km/h. He diverts his attention from the road to text a friend and drives into the back end of the car in front of him, moving them both at a speed of 40 km/h. If the second car has a mass of 1000 kg, how fast was it traveling prior to the collision?

• 0 m/s

• 10 m/s

• 20 m/s

• 30 m/s

A 3000 kg truck traveling at 50 m/s strikes a stationary 1000 kg car, locking the two vehicles together. What is the final velocity of the two vehicles?

• 1.5 x 10^5 m/s

• 5 x 10^4 m/s

• 6 x 10^1 m/s

• 3.75 x 10^1 m/s

A baseball (1 kg) coming from the East is approaching Barry at 10 m/s. Barry hits the baseball back to where it came from and the baseball leaves his bat at 10 m/s. What is the impulse Barry delivered to the baseball?

• 0 Ns west

• 10 Ns east

• 20 Ns east

• 20 Ns west

A roller coaster cart has a mass of 290 kg. Starting from rest the cart acquires 3.13x10^5 joules of Kinetic energy as it descends to the bottom of a hill in 5.3 seconds. Calculate the height of the hill.

• 230 m

• 110 m

• 145 m

• 470 m

A pitcher throws a 0.14-kilogram baseball in a straight line. Its momentum is 2.1 kg·m/sec. What is the velocity of the ball?

Answer : 15m/s

In a curling match, a 6.0­kg rock with speed 3.50 m/s collides with another motionless 6.0­kg rock. What are the velocities of the rocks after the collision if it is elastic?

• 1.75 m/s

• 0.65 m/s

• 14 m/s

• 0 m/s

A 6.0-kilogram block, sliding to the east across a

horizontal, frictionless surface with a momentum of

30. kilogram•meters per second, strikes an obstacle.

The obstacle exerts an impulse of 10. newton•seconds

to the west on the block. The speed of the block after

the collision is

• 1.7 m/s

• 3.3 m/s

• 5.0 m/s

• 20 m/s

A constant braking force of 10 Newtons applied for 5

seconds is used to stop a 2.5-kilogram cart traveling

at 20 meters per second. The magnitude of the

impulse applied to stop the cart is

• 10 Ns

• 30 Ns

• 50 Ns

• 100 Ns