## Electric Vehicle Basics

Assume in the following circuit we have a 12V battery and the resistance across the motor when running without a load is 40 ohms.

- How much current, in mA, will flow through the motor?
- What is the power, in watts, dissipated by the motor?
- If the motor ran for 10 minutes under the above conditions, what is the minimum battery capacity in mAh?

##
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__**Hint**

**Hint**

$$$Power=voltage \times current$$$

##
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__**Hint 2**

**Hint 2**

Ohm's Law

$$$V=iR$$$

where
$$V$$
is the voltage,
$$i$$
is the current, and
$$R$$
is the resistance.

To solve for the current, use Ohm's law:

$$$V=IR$$$

where
$$V$$
is the voltage,
$$I$$
is the current, and
$$R$$
is the resistance.

$$$I=\frac{V}{R}=\frac{12V}{40\Omega }=0.3A=300\:mA$$$

Power absorbed by a resistive element:

$$$P=VI$$$

where
$$P$$
is power,
$$V$$
is the voltage, and
$$I$$
is the current.

Solving for power dissipated by the motor:

$$$P=12V\times 0.3A=3.6\:W$$$

To solve for capacity:

$$$300mA \times 10min \times\frac{1h}{60min}=50\:mAh$$$

Current = 300 mA

Power = 3.6 W

Capacity = 50 mAh