Question

Какая масса воды образуется при 80 градусов изо льда при температуре равной -5 градусов, если сгорает 4 килограмма древесного угля, при КПД = 25%?

Answer 1

Если думать логически то получается толстый слой льда

Answer 2

Calculation of Water Mass Formed from Ice

To calculate the mass of water formed from ice at a temperature of -5 degrees Celsius when heated to 80 degrees Celsius, we need to consider the heat transfer and the specific heat capacity of ice and water.

The formula to calculate the heat transfer is:

Q = m * c * ΔT

Where: - Q is the heat transfer (in Joules) - m is the mass of the substance (in kilograms) - c is the specific heat capacity of the substance (in J/kg·°C) - ΔT is the change in temperature (in °C)

First, let's calculate the heat transfer from the burning of 4 kilograms of charcoal. Given that the efficiency (η) is 25%, we can calculate the heat produced (Q_charcoal) using the formula:

Q_charcoal = m_charcoal * ΔH_charcoal / η

Where: - m_charcoal is the mass of charcoal burned (in kilograms) - ΔH_charcoal is the heat of combustion of charcoal (in J/kg)

Since the heat of combustion of charcoal is not provided, we will assume a typical value of 30,000,000 J/kg.

Q_charcoal = 4 kg * 30,000,000 J/kg / 0.25 = 480,000,000 J

Next, let's calculate the heat transfer from the ice to water. The specific heat capacity of ice (c_ice) is approximately 2,090 J/kg·°C and the specific heat capacity of water (c_water) is approximately 4,186 J/kg·°C The change in temperature (ΔT) is 80°C - (-5°C) = 85°C.

Q_ice = m_ice * c_ice * ΔT_ice Q_water = m_water * c_water * ΔT_water

Since the mass of ice (m_ice) and water (m_water) are the same, we can combine the equations:

Q_ice = Q_water

m_ice * c_ice * ΔT_ice = m_water * c_water * ΔT_water

We can rearrange the equation to solve for the mass of water (m_water):

m_water = (m_ice * c_ice * ΔT_ice) / (c_water * ΔT_water)

Substituting the known values:

m_water = (m_ice * 2,090 J/kg·°C * 85°C) / (4,186 J/kg·°C * 85°C)

Simplifying the equation:

m_water = m_ice * 2,090 / 4,186

Now, we need to determine the mass of ice (m_ice). Unfortunately, the mass of ice is not provided in the question. Therefore, we cannot provide a specific answer to the question without this information.

Please provide the mass of ice so that we can calculate the mass of water formed.