A microphone converts:

Show by calculations that the above data verifies the law of conservation of energy(Neglect air resistance). ($\mathrm{g}=10 \raisebox{1ex}{$\mathrm{m}$}\!\left/ \!\raisebox{-1ex}{${\mathrm{s}}^2$}\right.$)

A ball falls to the ground as shown below:

What is the kinetic energy of the ball when it hits the ground?

A ball falls to the ground as shown below:

What is the potential energy of the ball at B?

A ball falls to the ground as shown below:

Which law can be used to calculate the potential and kinetic energy at point B and C, respectively?

In an experiment to measure his power, a student records the time taken by him in running up a flight of steps on a staircase. Use the following data to calculate the power of the student:

Number of steps $=28$

Height of each step$=20 \mathrm{cm}$

Time taken $=5.4 \mathrm{s}$

Mass of student $=55 \mathrm{kg}$

Acceleration due to gravity$=9.8 \mathrm{m} {\mathrm{s}}^{-2}$

In loading a truck, a man lifts boxes of $100 \mathrm{N}$ each through a height of $1.5 \mathrm{m}$. How much work does he do in lifting one box?

In loading a truck, a man lifts boxes of $100 \mathrm{N}$ each through a height of $1.5 \mathrm{m}$. How much energy is transferred when one box is lifted?

In loading a truck, a man lifts boxes of $100 \mathrm{N}$ each through a height of $1.5 \mathrm{m}$.

If the man lifts 4 boxes per minute, at what power is he working?
$\left(\mathrm{g}=10 \raisebox{1ex}{$\mathrm{m}$}\!\left/ \!\raisebox{-1ex}{${\mathrm{s}}^2$}\right.\right)$