Question

Чему равна масса железной детали , если при ее охлаждении от 200 градусов до 20 градусов в окружающую среду было отдано 20,7 кДж теплоты

Answer 1

Из формулы количества теплоты: 
Q=c*m*(t2-t1) ( c=460Дж/кг*град ( железа), t1-начальная тепература=20град, t2-конечная=200град) , выразим массу: 
m=Q / c*(t2-t1). 
m=20700 / 460*(200 - 20)=0,25кг. (250грамм).

Answer 2

Calculating the Mass of the Iron Detail

To calculate the mass of the iron detail, we can use the formula:

Q = mcΔT

Where: - Q is the heat transferred (20.7 kJ) - m is the mass of the iron detail (to be calculated) - c is the specific heat capacity of iron (which is approximately 0.45 kJ/kg°C) - ΔT is the change in temperature (200°C - 20°C = 180°C)

Calculation

Using the formula, we can rearrange it to solve for the mass m:

m = Q / (cΔT)

Substitute the given values: - Q = 20.7 kJ - c = 0.45 kJ/kg°C - ΔT = 180°C

Now, let's calculate the mass: m = 20.7 / (0.45 * 180)

m ≈ 0.256 kg

So, the mass of the iron detail is approximately 0.256 kg.