Question

how long does it take a microwave of power 0.2kW to sue 10000 J of energy

Answer 1

Answer:

50s .

Explanation:

$\frak{\pink{Given}}\begin{cases}\textsf{ The power of microvave is 0.2kW .}\\\textsf{ Amount of energy is 10000 J .}\end{cases}$

Here the power of the microwave is 0.2kW . And as we know that ,

• Rate of doing work is called power .

So from the definition , we have ;

$\sf\longrightarrow Power =\dfrac{Work}{time}$

• Here the work done is equal to the energy consumed by the microwave i.e. 10000 J .So we can write it as ,

$\sf\longrightarrow Power =\dfrac{Energy}{time}$

$\sf\longrightarrow 0.2kW = \dfrac{10^4 J }{t}$

$\sf\longrightarrow 0.2 * 1000 W = \dfrac{10^4 J }{t}$

Cross multiply ,

$\sf\longrightarrow t = \dfrac{ 10^4 }{ 0.2 * 10^3}s=\dfrac{10^4}{2*10^2} s$

Simplify ,

$\sf\longrightarrow \boxed{\bf t = 50s}$

Hence the time taken is 50s .