An electric motor drawing 10 amps at 110 V in steady state produces shaft power at 9.7 Nm and 1000 RPM. For a first Law analysis and considering the motor as the control volume How much heat will be produced from the motor (in Watts)

The heat rate produced from the motor is 84.216 watts.

Explanation:

The electric motor receives power from electric current and releases power in the form of mechanical energy (torque) and waste heat and can be considered an stable-state system. The model based on the First Law of Thermodynamics for the electric motor is:

Where:

- Heat transfer from the electric motor, measured in watts.

- Electric power, measured in watts.

- Mechanical power, measured in watts.

The heat transfer rate can be calculated in terms of electric and mechanic powers, that is:

The electric and mechanic powers are represented by the following expressions:

Where:

- Current, measured in amperes.

- Steady-state voltage, measured in volts.

- Torque, measured in newton-meters.

- Angular speed, measured in radians per second.

Now, the previous expression for heat transfer rate is expanded:

The angular speed, measured in radians per second, can be obtained by using the following expression:

Where:

- Rotational rate of change, measured in revolutions per minute.

If , then:

Given that , , and , the heat transfer rate from the electric motor is:

The heat rate produced from the motor is 84.216 watts.

the diagram which shows forces as either balanced = same speed or unbalanced = accelerarting

ok

explanation: