Potential Energy

What type of energy is stored in the spring of a watch?

A block of mass $30 \mathrm{kg}$is pulled up a slope with a constant speed by applying a force of $200 \mathrm{N}$parallel the slope. $\mathrm{A}$ and $\mathrm{B}$ are initial and final positions of block. Calculate work done by the force in moving the block from $\mathrm{A}$ to $\mathrm{B}$. Also, calculate $\mathrm{P}.\mathrm{E}.$ gained by block.

Define kinetic energy, potential energy, force and work done. Also, state the law of conservation of energy.

A ball of mass $20 \mathrm{g}$falls from a height of $10 \mathrm{m}.$ It rebounds from the ground to $4 \mathrm{m}$. Find initial potential energy of ball.

A pump is used to lift $500 \mathrm{kg}$ of water from a depth of $80 \mathrm{m}$ in $10 \mathrm{s}.$ Calculate the work done by the pump. $(\mathrm{g} =10 {\mathrm{ms}}^{-2})$

A stone of mass $500 \mathrm{g}$is thrown vertically upwards with a velocity of $15 \mathrm{m}/\mathrm{s}$. Calculate the potential energy at the greatest height.

A boy weighing $25 \mathrm{kgf}$climbs up from the first floor at height $3 \mathrm{m}$above the ground to the third floor at height$7 \mathrm{m}$ above the ground. What will be the increase in his gravitational potential energy? $(\mathrm{Take} \mathrm{g} = 10 \mathrm{N}.{\mathrm{kg}}^{-1})$

In a dam generating hydroelectric power, waterfalls at a rate of $1000 {\mathrm{kgs}}^{-1}$ from a height of $100 \mathrm{m}.$ Calculate the initial potential energy of the water.