Answer:
3k mph
Explanation:
don't take my answer it is wrong
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:
The answer is choice (3)
Explanation: Land materials do require more energy than water to raise their temperature by one degree, hence why water gets heated a lot easier than something like wood.
To solve this problem it is necessary to apply the concepts related to the Stefan-Boltzman law that is responsible for calculating radioactive energy.
Mathematically this expression can be given as
Where
A = Surface area of the Object
Stefan-Boltzmann constant
e = Emissivity
T = Temperature (Kelvin)
Our values are given as
Replacing at our equation and solving to find the temperature 1 we have,
Therefore the the temperature of the coldest room in which this person could stand and not experience a drop in body temperature is 12°C
