Chapter 22, Problem 58A

a.

To determine

The joules of energy delivered by the battery to the motor each second.

Answer to Problem 58A

  $2520\text{J}$

Explanation of Solution

Given:

The current delivered by a battery, $I=210\text{A}$

The voltage supplied by a battery, $V=12\text{V}$

Formula used:

The electric power $\left(P\right)$ across a circuit is given by,

  $P=IV$

Where, I is the current and V is the potential difference.

And, the energy $\left(E\right)$ supplied/delivered during time $t$ is given by,

  $\begin{array}{c}E=Pt\\ =VIt\end{array}$

Calculation:

Using the above formula and the given values, the energy delivered by the battery to the motor each second will be,

  $\begin{array}{c}E=VIt\\ =\left(12\right)\left(210\right)\left(1\right)\\ =2520\text{J}\end{array}$

Conclusion:

Hence, theenergy delivered by the battery to the motor each second is $2520\text{J}$ .

b.

To determine

The power used by the motor in Watts.

Answer to Problem 58A

  $2520\text{W}$

Explanation of Solution

Given:

The current delivered by a battery, $I=210\text{A}$

The voltage supplied by a battery, $V=12\text{V}$

Formula used:

The electric power $\left(P\right)$ across a circuit is given by,

  $P=IV$

Where,

  $\begin{array}{l}I=\text{current through circuit}\\ V=\text{ potential difference applied}\end{array}$

Calculation:

Using the above formula and the given values, the power used by the motor will be,

  $\begin{array}{c}P=IV\\ =\left(210\right)\left(12\right)\\ =2520\text{W}\end{array}$

Conclusion:

Hence, thepower used by the motor is $2520\text{W}$ .