Question

срочно Какую массу воды можно нагреть, затратив800 кДж энергии, если известно, что воду нагревали от 100 С до 85 0 С? Удельная теплоёмкость воды 4200 Дж/кг 0 С. [3 б] ​

Answer 1

Ответ:

Дано: t1 = 10

t2 =50

Q=210 кДж  

СИ:210 кДж = 210*10^3

Ршение:

Q=cm(t2-t1)

m= Q/c(t2-t1)

m = 210*10^3/ 4200*50=1 кг

Ответ: 1 кг (или  литр воды)

Объяснение:

Answer 2

Calculation of the Amount of Water Heated

To calculate the mass of water that can be heated using 800 kJ of energy, we need to use the specific heat capacity of water and the temperature change.

Given: - Energy input: 800 kJ - Initial temperature: 100 °C - Final temperature: 85 °C - Specific heat capacity of water: 4200 J/kg·°C

To find the mass of water, we can use the formula:

Q = mcΔT

Where: - Q is the energy input in Joules (800 kJ = 800,000 J) - m is the mass of water in kilograms (what we want to find) - c is the specific heat capacity of water (4200 J/kg·°C) - ΔT is the change in temperature (final temperature - initial temperature)

Let's calculate the mass of water:

800,000 J = m * 4200 J/kg·°C * (85 °C - 100 °C)

Simplifying the equation:

800,000 J = m * 4200 J/kg·°C * (-15 °C)

Dividing both sides by -15 °C * 4200 J/kg·°C:

m = 800,000 J / (-15 °C * 4200 J/kg·°C)

Calculating the result:

m ≈ -3.968 kg

The negative sign indicates an error in the calculation. It is not possible to heat a negative mass of water. Therefore, there seems to be an error in the given information or calculation.

Please double-check the values provided and ensure they are correct.