Final answer:
To produce the same energy as the electric bulb, approximately 0.1111 grams of coal are needed.
Step-by-step explanation:
To find the amount of coal needed to produce the same amount of energy as an electric bulb of 200 watts consumed in 10 hours, we need to calculate the total energy consumed by the bulb. The total energy consumed by the bulb is given by the formula:
Total Energy = Power x Time
Plugging in the values:
Total Energy = 200 watts x 10 hours = 2000 watt-hours
Now, we can calculate how many kilograms of coal are needed. Since 1 gram of coal burning liberates 18KJ of energy, we need to convert the total energy from watt-hours to KJ:
Total Energy = 2000 watt-hours x (1 KJ / 1000 watt-hours) = 2 KJ
Now we divide the total energy by the energy liberated by 1 gram of coal to get the mass of coal needed:
Mass of Coal = Total Energy / Energy Liberated by 1 gram of coal
Substituting the values:
Mass of Coal = 2 KJ / 18 KJ/gram = 0.1111 grams
Therefore, approximately 0.1111 grams of coal are needed to produce as much energy as an electric bulb of 200 watts consumed in 10 hours.
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