Question

Mechanical power. Determine the following. (a) current (in A ) delivered to the motor A (b) energy (in MJ ) delivered to the motor by electrical transmission in 2.50 h of operation ]MJ (c) the cost to run the motor (in dollars) for 2.50 h, if the electric company charges 0.110/kWh

Answer 1

To calculate the current (I) delivered to a motor, use the formula I = P/V with the known power (P) and voltage (V). For energy delivered, multiply the power by time and convert to MJ. The cost to run the motor is found by multiplying the power (in kW), the operating time (in hours), and the cost per kWh.

Step-by-step explanation:

To determine the current delivered to the motor (a), we would need the power P (in W) and the voltage V (in V) that the motor operates at, with the formula I = P/V, where I is the current in amperes (A).

For the energy delivered to the motor in a specific time (b), you multiply the power P consumed by the motor by the operating time t (in seconds) to get the energy in joules (J), and then convert joules to megajoules (MJ) where 1 MJ = 1,000,000 J.

To determine the cost to run the motor for a given time (c), use the formula: Cost = (Power in kW) x (time in hours) x (cost per kWh), ensuring that you convert the power from watts to kilowatts (1 kW = 1000 W) before performing the calculation.