Question

How much work is done using a 500-watt microwave oven for 5 minutes?

Answer 1

Power is the amount of energy per unit of time transferred or converted. The unit of power in the International System of Units is watts, equal to one joule per second. Power is sometimes referred to as action in older works. Calculate work done by the help of Power and time taken by the body.

Formula used:
$\text{W}=\text{P}\times \text{t}$
W= work done by the body
P= power consumed by the body
T= time taken by the body

Complete solution:
Energy and power are closely related, but the physical quantity is not the same. Energy is the ability to cause change; power is the rate of movement or utilization of energy.

Power is the rate at which work is done and can be expressed by the equation:
$\mathrm{P}=\dfrac{\mathrm{W}}{\mathrm{t}}$ with units of Watts (W).

We are given $\mathrm{P}=500 \mathrm{~W}$ and $\mathrm{T}=5 \mathrm{~min}=300 \mathrm{~s}$.

We can use these values to calculate the work done.
$\Rightarrow \text{W}=\text{P}\times \text{t}$
$=(500 \mathrm{~W}) \cdot(300 \mathrm{~s})$
$150,000 \mathrm{~J} \Rightarrow 1.5 \times 10^{5} \mathrm{~J}$

The unit of Watts is equivalent to joules per second, so we can see that the units work out.

Note:
Power is the rate at which the transfer of energy takes place. It is not energy, but it is often mistaken for energy. The watt is the most common unit of measurement used for power. It measures the energy transfer rate. The authority a local government has to collect taxes is an example of power. A watt (W) is a power unit, and power is the rate at which it produces or consumes energy. Think of watts as an electrical flow measure.