Momentum and Energy

As a student walks downhill at constant speed,

his gravitational potential energy

• increases and his kinetic energy increases

• increases and his kinetic energy remains the

  same

• decreases and his kinetic energy increases

• decreases and his kinetic energy remains the

  same

Two construction cranes are used to lift identical

1200-kilogram loads of bricks the same vertical

distance. The first crane lifts the bricks in

20. seconds and the second crane lifts the bricks

in 40. seconds. Compared to the power

developed by the first crane, the power

developed by the second crane is

• the same

• twice as great

• half as great

• four times as great

A 1.47-newton baseball is dropped from a height of 10.0 meters and falls through the air to the ground. The kinetic energy of the ball is 12.0 joules the instant before the ball strikes the ground. The maximum amount of mechanical energy converted to internal energy during the fall is

• 2.7 J

• 12.0 J

• 14.7 J

• 26.7 J

The amount of electric energy consumed by a 60.0-watt lightbulb for 1.00 minute could lift a 10.0 newton object to a maximum vertical height of

• 6.00 m

• 36.7 m

• 360. m

• 600. m

A tennis player’s racket applies an average force of 200. newtons to a tennis ball for 0.025 second. The average force exerted on the racket by the tennis ball is

• 0.025 N

• 200. N

• 5.0 N

• 80.0 N

A blue lab cart is traveling west on a track when it collides with and sticks to a red lab cart traveling east. The magnitude of the momentum of the blue cart before the collision is 2.0 kilogram • meters per second, and the magnitude of the momentum of the red cart before the collision is 3.0 kilogram • meters per second. The magnitude of the total momentum of the two carts after the collision is

• 1.0 kg • m/s

• 2.0 kg • m/s

• 3.0 kg • m/s

• 5.0 kg • m/s

The momentum of an object depends upon the object's ___________&_____________.  

• size and shape
• mass and speed
• mass and veloctiy
• mass and energy

The equation to calculate momentum is

• p=mv
• p=1/2mv²
• p=mgh
• p=mg

In any collision (crash) the ______ is ALWAYS constant

• Total Momentum
• total speed
• total Velocity
• Energy

A 9 kg blob moving at 5 m/s collides and sticks to a second blob with a mass of 5 kg. If the two bobs stick together, what will the velocity of the two blobs move at?

• 3.57 m/s
• 3.2 m/s
• 10.0  m/s
• 9.0  m/s