A 120-V motor has mechanical power output of 3.00 hp. It is 94.0% efficient in converting power that it takes in by electrical transmission into mechanical power. Find the energy delivered to the motor by electrical transmission in 2.00 h of operation. Do i divide the power by .94 or time it by .94
Divide by 0.94. It will take about 6% more electrical power than the mechanical power delivered to the output.
To find the energy delivered to the motor by electrical transmission in 2.00 hours of operation, you need to consider both the power output of the motor and its efficiency.
First, let's convert the power output of the motor from horsepower (hp) to watts (W). We know that 1 hp is equal to 745.7 W, so the power output of the motor is:
3.00 hp * 745.7 W/hp = 2237.1 W
Next, we need to account for the efficiency of the motor. Since the motor is 94.0% efficient, only 94.0% of the electrical power transmitted to the motor is converted into mechanical power. To calculate the electrical power transmitted to the motor, we divide the power output by the efficiency:
Electrical power = Power output / Efficiency
= 2237.1 W / 0.940
= 2379.3 W
Now that we have the electrical power transmitted to the motor, we can find the energy delivered by multiplying it by the time of operation:
Energy = Electrical power * Time
= 2379.3 W * 2.00 hours
= 4758.6 Wh (Watt-hours)
So, the energy delivered to the motor by electrical transmission in 2.00 hours of operation is 4758.6 Watt-hours.