What is the Energy Consumed When a 15hp Horse Power Motor is Run for 2 Hours in Joules?

Understanding Power and Time in the Context of Energy Consumption

Energy is often expressed as the product of power and time. Power is the rate at which work is done, typically measured in watts (W). Time is usually measured in seconds (s).

Converting Horsepower to Kilowatts

First, let's start with the conversion of horsepower (hp) to kilowatts (kW). One horsepower is approximately equal to 0.746 kilowatts. Given a 15 hp motor:

Power 15 hp x 0.746 kW/hp 11.19 kW

Calculating the Output Energy in Joules

The relationship between power, time, and energy is given by the formula:

Energy Power x Time

If the motor runs for 2 hours, the time in seconds is:

Time 2 hours x 3600 seconds/hour 7200 seconds

Calculating the Output Energy

Now, let's calculate the output energy in joules:

Energy 11.19 kW x 7200 s 80.13 MJ (megajoules)

Converting Energy Consumption to Megajoules

So, the output energy produced by the motor is approximately 80.13 MJ, or 80,130,000 joules.

Understanding Input Power and Efficiency

However, the actual energy consumed by the motor might be higher due to inefficiencies in the generator or motor. If the generator is only 25% efficient, the input power required would be:

Input Power Output Energy / Efficiency

Input Energy 80.13 MJ / 0.25 320.52 MJ (megajoules)

Practical Applications and Considerations

This calculation is crucial for engineers, HVAC technicians, and anyone dealing with power consumption in industrial settings. It helps in optimizing energy usage, reducing costs, and ensuring efficient operation of machinery.

Key Takeaways

Energy is the product of power and time. 15 hp is approximately equal to 11.19 kW. 2 hours of operation equates to 7,200 seconds. The output energy is 80.13 MJ, or 80,130,000 joules. Considering an efficiency of 25%, the input energy needed is 320.52 MJ.

Further Reading and Resources

For more detailed information on power consumption, efficiency, and energy conversion, visit this link to explore comprehensive guides and case studies.