Question

Какое количество теплоты надо сообщить бруску льда массой 3 кг и температурой 0 градусов,чтобы получить воду температурой 20 градусов?Помогите плииз!

Answer 1

$Q=Q_1+Q_2=\lambda m+Cm(t_2^o-t_1^o)=m[\lambda+C(t_2^o-t_1^o)]\\ Q=3*[340000+4200*(20-0)]=1272000Dg=\bf 1272kDg$

Answer 2

Calculating Heat Required to Melt Ice

To calculate the amount of heat required to melt the ice, we can use the formula:

Q = m * L

Where: - Q = heat required (in joules) - m = mass of the ice (in kg) - L = specific latent heat of fusion for ice (in J/kg)

Given: - m = 3 kg - Initial temperature of the ice = 0°C - Final temperature of the water = 20°C

We need to calculate the heat required to melt the ice and raise the temperature of the resulting water to 20°C.

Specific Latent Heat of Fusion for Ice

The specific latent heat of fusion for ice is approximately 334,000 J/kg.

Calculation

Using the formula Q = m * L, we can calculate the heat required to melt the ice:

Q1 = m * L Q1 = 3 kg * 334,000 J/kg Q1 = 1,002,000 J

So, the heat required to melt the ice is 1,002,000 joules.

Heating the Water

To raise the temperature of the resulting water from 0°C to 20°C, we can use the formula:

Q2 = m * c * ΔT

Where: - Q2 = heat required (in joules) - m = mass of the water (in kg) - c = specific heat capacity of water (in J/kg°C) - ΔT = change in temperature (in °C)

The specific heat capacity of water is approximately 4,186 J/kg°C.

Using the formula Q2 = m * c * ΔT, we can calculate the heat required to raise the temperature of the water:

Q2 = 3 kg * 4,186 J/kg°C * 20°C Q2 = 251,160 J

So, the heat required to raise the temperature of the resulting water to 20°C is 251,160 joules.

Total Heat Required

The total heat required is the sum of the heat required to melt the ice and the heat required to raise the temperature of the resulting water:

Total Heat Required = Q1 + Q2 Total Heat Required = 1,002,000 J + 251,160 J Total Heat Required = 1,253,160 J

Therefore, the total amount of heat that needs to be supplied to the ice to obtain water at 20°C is 1,253,160 joules.