Work and Energy Science - Work and Energy

1. Electric motor.
2. Alternator.
3. Turbine.
4. Electric heater.

1. Hydroelectric power stations use water to drive turbines.
2. In a power station, turbines drive generators.
3. Electricity from thermal power stations differs from that produced in hydroelectric power stations.
4. In hydroelectric power stations and thermal power stations, alternators produce electricity.

1. Increases.
2. Decreases.
3. Remains constant.
4. First increases and then decreases.

The work done on an object does not depend on the:

1. Displacement.
2. Angle between force and displacement.
3. Force applied.
4. Initial velocity of the object.

 In case of negative work, the angle between the force and displacement is:

1. 0°
2. 45°
3. 90°
4. 180°

Is potential energy a vector or a scalar quantity?

1. In the battery.
2. In the bulb.

1. Maximum potential energy?
2. Maximum kinetic energy?

1. ♦ Potential energy = 80 J, Kinetic energy = 0
2. ♦ Kinetic energy = 48J
3. ♦ Potential energy = 0

1. What is the kinetic energy of ball when it hits the ground?
2. What is the potential energy of ball at B?
3. Which law you have made use of in answering this this question?

1. Work done by the car.
2. Power of engine of car.

1. A ball thrown upwards.
2. A stone dropped from the roof of a building.

A body of 2kg falls from rest. What will be its kinetic energy during the fall at the end of 2s? (Assume g = 10m/s²)