$A$ crane pulls up a car weighing $500 \, kg$ to a vertical height of $4 \, m$. Calculate the work done by the crane. (in $J$)

$A$ light and a heavy object have the same momentum. Find out the ratio of their kinetic energies. Which one has a larger kinetic energy?

An iron sphere of mass $10 \, kg$ has the same diameter as an aluminium sphere of mass $3.5 \, kg$. Both spheres are dropped simultaneously from a tower. When they are $10 \, m$ above the ground,they have the same

State whether the following statement is true or false:
When energy changes from one form to another,the energy that disappears from one form reappears in an exactly equivalent amount in the other form.

An object of mass $40 \text{ kg}$ is pulled up to a height of $0.5 \text{ m}$. Calculate the work done. (Given $g = 9.8 \text{ m s}^{-2}$) (in $J$)

State the relation between $kWh$ and joule. Define $1$ watt.