Two coolies A and B do some work in time 1 minute and 2 minute respectively. The power spent is:

1. same by both coolies
2. is more by coolie A than by B
3. is less by coolie A than by B
4. nothing can be said

The expression of power P is:

1. P = mgh
2. P = $\dfrac{\text{1}}{\text{2}}$ mv²
3. P = F x d
4. P = F x $\dfrac{\text{d}}{\text{t}}$

When a boy doubles his speed, his kinetic energy becomes:

1. half
2. double
3. four times
4. no change

A boy lifts a luggage from height 2 m to 4 m. The potential energy will become:

1. half
2. double
3. one-third
4. one-fourth