9 weeks review Work, Power, Energy, Momentum and Thermodynamics

Water in an ice cube tray is put into the freezer section of a refrigerator. As it freezes, this water —

• loses all entropy

• increases in entropy

• decreases in entropy

• has constant entropy

  CLEAR ALL

As the temperature of a fluid

decreases—

• The number of inter-particle collisions and random movement of particles decrease.

• The number of inter-particle collisions and random movement of particles increase.

• The number of inter-particle collisions increase and random movement of particles decrease.

• The number of inter-particle collisions decrease and random movement of particles increase.

Billiard ball A (0.35 kg) is struck such that it moves at 10 m/s toward a second identical ball (Ball B). After the collision Ball A continues to move in the same direction at 2 m/s. What is the momentum of ball A before the collision?

• 0

• 3.5 kg m/s

• 20 kg m/s

• 10 kg

Billiard ball A (0.35 kg) is struck such that it moves at 10 m/s toward a second identical ball (Ball B). After the collision Ball A continues to move in the same direction at 2 m/s. What is the momentum of ball A after the collision?

• 0

• 10 m/s

• .7 kg m/s

• 10 kg

Billiard ball A (0.35 kg) is struck such that it moves at 10 m/s toward a second identical ball (Ball B). After the collision Ball A continues to move in the same direction at 2 m/s. What is the magnitude of the velocity for Ball B after the collision?

• 8 m/s

• 20 m/s

• 0

Student A lifts a 50-newton box from the floor to a height of 0.40 meters in 2.0 seconds. Calculate the work done by student A?

• 50 J

• 20 J

• 0

• 100 j

Student A lifts a 50-newton box from the floor to a height of 0.40 meters in 2.0 seconds. Calculate the power student A produced?

• 50 N

• 100 Watts

• 10 Watts

• 0

Student B lifts a 40-newton box from the floor to a height of 0.50 meters in 1.0 second. Calculate the work done by Student B.

• 20 J

• 0

• 100 J

An airbag is used to safely decrease the momentum of a driver in a car accident. Which of the following are true about how the airbag protects the driver?

• The air bag increases the length of time the force acts on the driver.

• The air bag increases the rate of acceleration of the driver.

• The air bag decreases the mass of the driver.

An airbag is used to safely decrease the momentum of a driver in a car accident. Which of the following are true about how the airbag protects the driver?

• The air bag acts to prevent collisions with other vehicles.

• The air bag has magnets which repel it from other cars.

• The air bag has flexibility which helps reduce the effects of the impact force.