Energies - chemical and electrical (easy question)

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SUMMARY

The discussion focuses on the relationship between chemical energy and electrical energy in a battery-powered motor system. The battery starts with 36,000J of chemical energy, and after the motor uses 22J, 35,978J of chemical energy remains. The user questions whether electrical energy is equivalent to the chemical energy used, and confirms that with 100% efficiency, 22J of chemical energy converts to 22J of electrical energy. However, due to the motor's 5% efficiency, the actual work done requires multiplying the energy used by 20 to determine the change in chemical energy.

PREREQUISITES
  • Understanding of chemical energy and its conversion to electrical energy
  • Basic knowledge of motor efficiency and energy loss
  • Familiarity with energy units (Joules)
  • Concept of energy conservation in electrical systems
NEXT STEPS
  • Research the principles of energy conversion in batteries and motors
  • Learn about efficiency calculations in mechanical systems
  • Explore the concept of thermal energy generation in electrical devices
  • Study the laws of thermodynamics as they apply to energy systems
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Students in physics or engineering, electrical engineers, and anyone interested in understanding energy transformations in battery-operated devices.

Melawrghk
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I have to graph changes in energies. And I have a question - so I have a battery that supplies power to a motor and some sensors. I have to assume it starts with 36000J of energy (chemical energy, right?). Then, pretend a motor uses 22J and shuts off. Now I would have 35978J of chemical left. But what about electrical? Is it the same as chemical in this case? Or is it equivalent to just the value of chemical used? So 22J...

Also, I know the motor is 5% efficient. So if I know how much work it did on a certain item, would I have to multiply it by 20 to get the change in chemical energy?

Thanks bunches :)
 
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Melawrghk said:
I have to graph changes in energies. And I have a question - so I have a battery that supplies power to a motor and some sensors. I have to assume it starts with 36000J of energy (chemical energy, right?). Then, pretend a motor uses 22J and shuts off. Now I would have 35978J of chemical left. But what about electrical? Is it the same as chemical in this case? Or is it equivalent to just the value of chemical used? So 22J...
Supposing 100% efficiency, 22J of chemical energy are turned into 22J of electrical energy by the battery, then into 22J of mechanical energy by the motor.
Also, I know the motor is 5% efficient. So if I know how much work it did on a certain item, would I have to multiply it by 20 to get the change in chemical energy?

Thanks bunches :)

Yes, and 19 x 22J of chemical energy are turned into the same amount of thermal energy.
 

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