Question

Какой объем воды можно нагреть от 20 градусов до температуры кипения за счет тепла, полученного при сжигании 0,5 л керосина? Считайте, что все количество теплоты, выделившееся при сгорании керосина, идет на нагрев воды. Очень срочно 8 класс

Answer 1

1) при сгорании Q=qm=4,6*10^7 Дж/кг
2) нагревание воды Q=cm(t2-t1), 4,6*10^7=4200*m*(100-20),
m=4,6*10^7Дж/4200 (Дж/кг*гр.)*80гр.=0,14*10^3кг=примерно 140 кг
Так много, т.к. не учитывали потери, а они оч. большие. Паровоз теряет 96% тепла от сгорания угля!!!!!!

Answer 2

Calculating the Heat Energy Required to Heat Water

To calculate the heat energy required to heat water from 20°C to its boiling point using the heat released from burning kerosene, we can use the formula:

Q = mcΔT

Where: - Q = heat energy (in joules) - m = mass of water (in grams) - c = specific heat capacity of water (in J/g°C) - ΔT = change in temperature (in °C)

Specific Heat Capacity of Water

The specific heat capacity of water is approximately 4.18 J/g°C.

Change in Temperature

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

Mass of Water

To find the mass of water, we can use the density of water, which is approximately 1 gram per milliliter. Given that we have 0.5 liters of water, the mass can be calculated as follows:

Density = Mass / Volume

Mass = Density × Volume

Mass = 1 g/mL × 500 mL

Mass = 500 grams

Calculating the Heat Energy

Using the formula Q = mcΔT: Q = 500g × 4.18 J/g°C × (100°C - 20°C)

Q = 500g × 4.18 J/g°C × 80°C

Q = 167200 J

Therefore, the heat energy required to heat 0.5 liters of water from 20°C to its boiling point is approximately 167200 joules.

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