Physics, asked by sasarita8331, 11 months ago

One gram of coal burning liberates 18 kj of energy . How many kilograms of coal will produce as much energy as an electric bulb of 200w consumed in 10 hours.

Answers

Answered by Anonymous
32

Given, Power of bulb = 200 watt or 200 Joules per second

given Time = 10 Hours

•°• Total power consumed by the electric bulb in 10 Hours = 200 * 10 * 3600 ( because we are given Power consumed by the bulb is 200 Joules in 1 second , Therefore we should convert the given time ( 10 Hours ) into seconds. Since 1 Hr = 60 minute = 60 * 60 seconds )

=> 2000 * 3600

=> 72,00,000 Joules or 7200 KJ ( because 1000 J = 1 KJ

Since 1 gram of coal liberates 18 KJ of energy.

•°• Grams of coal which will liberate 7200 KJ will be:

= 7200 ÷ 18

= 400

Therefore, 400 Gram of coal will produce as much energy as an electric bulb of 200 W for 10 Hours.

Answered by Anonymous
39

Answer:

Given :

Power = 200 W

We know :

Power mean energy consumed per second i.e. J / sec

Energy consumed by bulk in 10 hours  = 200 × 60 × 60 × 10J

Energy consumed by bulk in 10 hours in kJ = 200 × 60 × 60 × 10 / 1000 kJ

Energy consumed by bulk in 10 hours in kJ = 200 × 36 kJ

1 g coal burning liberates 18 kJ

Therefore , required gram of coal burning liberates = 200 × 36 / 18 g

Finally , it will liberates 400 grams or 0.4 kg .

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