Chapter 6.3, Problem 21PP

To determine

To calculate: Time for which the TV was on during the day.

Answer to Problem 21PP

The TV was on for $\underset{\_}{\text{4 h}}$ .

Explanation of Solution

Given:

Power = $\text{200 W}$

Electrical energy = $\text{0}\text{.8 kWh}$

Formula used:

Electrical energy is given by,

  $E=Pt$

where $P$ is power and $t$ is time.

Calculation:

Time is calculated as:

  $\begin{array}{l}E=Pt\\ t=\frac{E}{P}\\ =\frac{0.8\text{ kWh}}{200\text{ W}}\\ =\frac{0.8\times 1000\text{ W}}{200\text{ W}}\\ =4\text{ h}\end{array}$

Conclusion:

The TV was on for $\underset{\_}{\text{4 h}}$ .