Question

9. How much energy does a 100 W light bulb use in half an hour? If the light bulb converts

Answer 1

The energy used by the light bulb in half an hour is 180000 J and the amount of thermal energy generated is 158400 J.

What is Energy?

Energy is the ability or the capacity to do work.

To calculate the energy of the light bulb we use the formula below

Formula:

• E = Pt.......... Equation 1

Where:

• E = Energy used by the bulb in a half-hour
• P = Power of the bulb
• t = Time

Given:

• P = 100 W
• t = 1/2 hour = 30 minutes = (30×60) = 1800 seconds

Substitute these values into equation 1

• E = (100×1800)
• E = 180000 J

• If the light converts 12% of electric energy to light energy, then  88% of the energy is used to generate thermal energy

Therefore,

• Thermal energy = (180000×88/100) = 158400 J

Hence, the energy used by the light bulb in half an hour is 180000 J and the amount of thermal energy generated is 158400 J.

Learn more about energy here: brainly.com/question/21927255

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