Question

У 250 г води за температури 15°C вкинули грудочку мокрого снігу масою 20 г.Теплова рівновага встановилася за температури 10°C.Скільки води було у снігові?

Answer 1

Ответ:

m1 = 250 г = 0,25 кг

m + m2  = 20 г = 0,02 кг

t1 = 15 *C

∆t = 5 *C

___________________

m2 - ?

 

Решение:

Вода, находящаяся в калориметре бyдет охлаждаться: Q1  = cm1∆t

Снег в комке будет таять: Q2 = λm  и затем образовавшаяся вода будет нагреваться от 0 *С до t-∆t  = 10 *C: Q3 = cm( t-∆t -0). Вода в комке снега будет нагреваться: Q4 = cm2( t-∆t -0)

Составим уравнение теплового баланса:

Q1 = Q2 + Q3 + Q4

cm1∆t = λm + cm( t-∆t -0) + cm2( t-∆t -0), m = 0.02 - m2

cm1∆t = λ(0.02-m2) + c(0.02-m2)( t-∆t ) + cm2( t-∆t)

4200*0.25*5 = 340000(0,02-m2) + 4200(0.02-m2)*10 + 4200m2*10

5250 = 6800 - 340000m2 + 840 - 42000m2 + 42000m2

m2 = 0.007 кг = 7 г

Объяснение:

Answer 2

Calculation of the amount of water in the snow

To calculate the amount of water in the snow, we can use the concept of specific heat capacity. The specific heat capacity of water is 4.18 J/g°C, which means that it takes 4.18 Joules of energy to raise the temperature of 1 gram of water by 1 degree Celsius.

Given: - Initial temperature of the water: 15°C - Mass of the water: 250 g - Mass of the wet snowball: 20 g - Final temperature after thermal equilibrium: 10°C

To find the amount of water in the snow, we need to calculate the heat transferred from the water to the snowball.

Calculation steps:

1. Calculate the heat transferred from the water to the snowball: - Heat transferred = (mass of water) * (specific heat capacity of water) * (change in temperature) - Heat transferred = (250 g) * (4.18 J/g°C) * (15°C - 10°C)

2. Calculate the mass of water in the snowball: - Heat transferred = (mass of water in snowball) * (specific heat capacity of water) * (change in temperature) - (mass of water in snowball) = Heat transferred / (specific heat capacity of water) / (change in temperature) - (mass of water in snowball) = (Heat transferred) / (4.18 J/g°C) / (15°C - 10°C)

Calculation:

Let's calculate the mass of water in the snowball:

1. Calculate the heat transferred from the water to the snowball: - Heat transferred = (250 g) * (4.18 J/g°C) * (15°C - 10°C) - Heat transferred = 250 g * 4.18 J/g°C * 5°C - Heat transferred = 5235 J

2. Calculate the mass of water in the snowball: - (mass of water in snowball) = (5235 J) / (4.18 J/g°C) / (15°C - 10°C) - (mass of water in snowball) = 5235 J / 4.18 J/g°C / 5°C - (mass of water in snowball) ≈ 250 g

Answer:

Based on the given information, the mass of water in the snowball is approximately 250 grams.