Question

Сколько керосина нужно сжечь,чтобы нагреть 1,5кг воды от 20°до 80°,если на её нагревание пошло половину тепла полученного в результате згорания ккросина

Answer 1

Отметьте как лучшее, пожалуйста!!

0,5Q1=Q2
Q1=m(к)q
Q2=c(в)m(в)Δt

0,5m(к)q=c(в)m(в)Δt
m(к)=c(в)m(в)Δt/0,5q
m(к)=4200*1,5*(80-20)/0,5*44*10^6=0,0172кг=17,2г

не знаю, какая у вас в задачнике удельная теплота сгорания керосина, но я взял за 44МДж/кг

Answer 2

Calculating the Amount of Kerosene Needed to Heat Water

To calculate the amount of kerosene needed to heat 1.5 kg of water from 20°C to 80°C, we can use the specific heat capacity of water and the energy released from burning kerosene.

The specific heat capacity of water is 4.18 J/g°C. This means that it takes 4.18 joules of energy to raise the temperature of 1 gram of water by 1 degree Celsius.

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

Q = mcΔT

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

Given: - m = 1.5 kg = 1500 g - c = 4.18 J/g°C - ΔT = 80°C - 20°C = 60°C

Using the formula, we can calculate the energy required to heat the water.

Q = 1500g * 4.18 J/g°C * 60°C = 376,200 J

Now, since it's mentioned that half of the heat produced from burning kerosene is used to heat the water, we need to find the total energy released from burning kerosene.

Let's proceed to calculate the amount of kerosene needed based on the energy released from burning it.