When we rub our hands

1. kinetic energy changes into potential energy
2. mechanical energy changes into heat energy
3. potential energy changes into kinetic energy
4. heat energy changes into mechanical energy

A ball rolling on the ground possess

1. kinetic energy
2. potential energy
3. no energy
4. heat energy

When a bulb lights up on passing current, the change of energy is

1. from electrical energy to heat energy
2. from electrical energy to light energy
3. from electrical energy to heat and light energy
4. from electrical energy to mechanical energy

The correct statement is

1. Both work and energy have the same units
2. Potential energy of a body is due to its motion
3. Kinetic energy of a body is due to its position or state
4. Kinetic energy can change into potential energy, but potential energy cannot change into kinetic energy