Question

Какое количество керосина необходимо сжечь, чтобы 50 л воды нагреть от 200С до кипения? К.П.Д. нагревателя 35%.

Answer 1

Q1=qm
Q2=Cm(t2-t1) 
0.35Q1=Q2 

q керосина = 43*10^6

C воды = 4200

если вы все-таки подразумевали "нагреть от 20 градусов", то вот решение:
0.35qm(керосина)=С(воды)m(воды)(t2-t1)

m(керосина)=С(воды)m(воды)(t2-t1)/0.35q
m=4200*50*80/0.35*43000000=1.17

ответ: 1.17  кг
 

Answer 2

Calculation of the Amount of Kerosene Required to Heat 50 Liters of Water

To calculate the amount of kerosene required to heat 50 liters of water from 20°C to its boiling point, we need to consider the specific heat capacity of water and the efficiency of the heater.

The specific heat capacity of water is approximately 4.2 kJ/kg°C Assuming the density of water is 1 kg/L, the mass of 50 liters of water is 50 kg.

The formula to calculate the heat energy required to raise the temperature of a substance is:

Q = m * c * ΔT

Where: - Q is the heat energy - m is the mass of the substance - c is the specific heat capacity of the substance - ΔT is the change in temperature

In this case, the change in temperature is from 20°C to the boiling point of water, which is 100°C.

Let's calculate the heat energy required to heat 50 liters of water:

Q = 50 kg * 4.2 kJ/kg°C * (100°C - 20°C)

Q = 50 kg * 4.2 kJ/kg°C * 80°C

Q = 168,000 kJ

Now, let's take into account the efficiency of the heater. The efficiency of the heater is given as 35%.

The formula to calculate the energy input required is:

Energy Input = Q / Efficiency

Energy Input = 168,000 kJ / 0.35

Energy Input = 480,000 kJ

Therefore, to heat 50 liters of water from 20°C to its boiling point, approximately 480,000 kJ of energy input is required.

Please note that this calculation assumes ideal conditions and does not take into account any heat losses during the heating process.