Question

Сколько кг каменного угля нужно сжечь для получения 700кДжколичества теплоты

Answer 1

Q=qm
m=Q/q
700 кДж=700000 Дж
q=29 МДж=29000000 Дж
m=700000/29000000=0,02 кг

Answer 2

Calculating the Amount of Coal Needed to Produce 700 kJ of Heat Energy

To calculate the amount of coal needed to produce 700 kJ of heat energy, we can use the calorific value of coal, which is the amount of heat energy produced per unit mass of coal burned.

The calorific value of coal is typically given in units of kJ/kg, which represents the amount of heat energy produced by burning 1 kilogram of coal.

Calculation:

To find the amount of coal needed to produce 700 kJ of heat energy, we can use the following formula:

Amount of coal (in kg) = Heat energy required (in kJ) / Calorific value of coal (in kJ/kg)

Calorific Value of Coal:

The calorific value of coal can vary depending on the type of coal. However, for the purpose of this calculation, we can use an average calorific value of coal, which is approximately 24 MJ/kg or 24,000 kJ/kg.

Using the formula, we can calculate the amount of coal needed:

Amount of coal (in kg) = 700 kJ / 24,000 kJ/kg

Calculation Result:

Calculating the result gives us:

Amount of coal ≈ 0.0292 kg

Therefore, approximately 0.0292 kilograms of coal would be needed to produce 700 kJ of heat energy.