Answer:
Explanation:
The interaction of the piece of copper and water means that the first one need to transfer heat in order to reach a thermal equilibrium with water. Then:
After a quick substitution, the expanded expression is:
The final temperature of the system is:
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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Answer:
refraction
Explanation: hope this helps :)
Using formula:
I=(1/2)*M*(R^2+r^2)
<span>I=0.5*0.715kg*[(12.7cm)^2+(10.7cm)^2] </span>
<span>I=98.6 kg*cm^2</span>
