Calculating Light Energy and Consumption: A 60W Bulb Left On for 10 Hours

  • Thread starter RMHAZARD
  • Start date
In summary, the conversation discusses calculating the amount of light energy produced by a 60 watt light bulb left on for 10 hours at 15% efficiency. The individual asks for clarification on finding the work done and the correct units to use, and ultimately determines the correct amount of energy produced to be 324000. The conversation also emphasizes the importance of stating units when discussing energy.
  • #1
RMHAZARD
24
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hi here is the question

A 60 watt light bulb is left swithed on for 10 hours. If the light bulb is 15% effcient, calculate the amount of light energy produced in that time. what is the total energy consumption of the light bulb in this time.

so i need to find work done right so is that power divided by time to get the energy and then find 15% of that am i right i am bathed by this.
 
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  • #2
A watt is 1 unit of energy per unit time. You know how much of the energy was turned into light (15%) and the length of time the light was left on. No need to introduce work.
 
  • #3
so do i divide watts by time taken?
 
  • #4
so 60 watts divided by10 hours which is 6 15% of 6 is 0.9 if i am correct

can you please tell me if i am right if not can you advive me where i went wrong
 
  • #5
your answer is incorrect. First you need to think about units
watts is per second whereas you're given a time in hours. Secondly do you think the energy would be lower or higher than how much you are using in one second?
 
  • #6
so 10 hours is 600 minutes 36000 seconds and 60 watts goes goes in in 36000 2160000 so 15% 324000 am i right
 
  • #7
Correct. now remember to state you units. energy is measured in...
 

What is energy and how is it defined?

Energy is the ability to do work or cause change. It can be defined as the capacity of a physical system to perform work. In simpler terms, energy is what allows things to happen.

What are the different forms of energy?

There are various forms of energy, including mechanical, thermal, electrical, chemical, and nuclear. Mechanical energy is the energy of movement, thermal energy is the energy of heat, electrical energy is the energy of moving electrons, chemical energy is the energy stored in bonds between atoms, and nuclear energy is the energy released from the nucleus of an atom.

What is the law of conservation of energy?

The law of conservation of energy states that energy cannot be created or destroyed, but can only be transformed from one form to another. This means that the total energy in a closed system remains constant.

How is energy measured?

The SI unit for energy is joule (J), but other units such as calorie, kilowatt-hour, and British thermal unit (BTU) are also commonly used. Energy can be measured using instruments such as a thermometer, a calorimeter, or a wattmeter.

What are the applications of energy in our daily lives?

Energy plays a crucial role in our daily lives. It powers our homes, transportation, and industries, and is essential for cooking, heating, and lighting. It is also used in the generation of electricity, production of goods, and in various forms of technology such as computers and smartphones.

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