Question

В бочку с водой опустили лед массой 2 кг при темпе­ратуре 0 °С. Сколько воды было в бочке, если после таяния льда температура воды уменьшилась от температуры 20 °С до температуры 18 °С?

Answer 1

Q1=лm1
Q2=cm(t2-t1)
л(лед)=330000Дж/кг
m1=2кг

c(вода)=4200 Дж/кг*K
(t2-t1)=20-18=2
m2=?
Для того чтобы расплавить 2 кг льда нам потребуется 330000*2=660000Дж

Для того чтобы найти массу воды, приравняем Q1 и Q2
получается 660000=4200*m2*2
Найдем m2
660000=8400*m2
m2=660000/8400=78.6кг
Ответ:78,6кг 

Answer 2

Calculating the Amount of Water in the Barrel

To calculate the amount of water in the barrel after the ice has melted, we can use the principle of the conservation of mass. The mass of the ice that has melted will be equal to the mass of the water that has been displaced.

Given: - Mass of ice (m_ice) = 2 kg - Initial temperature of ice (T_ice) = 0 °C - Initial temperature of water (T_water_initial) = 20 °C - Final temperature of water after ice melts (T_water_final) = 18 °C

We can use the specific heat capacity of water to calculate the amount of water in the barrel.

Solution

1. First, we need to calculate the heat absorbed by the ice to melt: - The specific heat capacity of ice (c_ice) = 2.09 J/g°C - The specific heat capacity of water (c_water) = 4.18 J/g°C - The heat absorbed by the ice to melt is given by the formula: Q = m_ice * c_ice * ΔT, where ΔT is the change in temperature from 0 °C to the melting point of ice (0 °C).

2. Then, we can calculate the heat released by the water when it cools down from 20 °C to 18 °C: - The heat released by the water is given by the formula: Q = m_water * c_water * ΔT, where m_water is the mass of water and ΔT is the change in temperature from 20 °C to 18 °C.

3. Equating the heat absorbed by the ice to the heat released by the water will allow us to solve for the mass of water in the barrel.

Calculation

Let's calculate the mass of water in the barrel using the above approach.