The refrigerator cools 1.5 liters of water from 16 ° C to 4 ° C in 20 minutes of operation.

The refrigerator cools 1.5 liters of water from 16 ° C to 4 ° C in 20 minutes of operation. How much ice was formed if the cooling process was continued for another 60 minutes in the same mode?

1. Water has lost energy:
Q = C * m * dT.
2. Power is equal to:
P = Q / t.
3. So for the remaining 60 minutes the refrigerator will take energy:
E = P * 60 * 60;
E = 3600 * P.
4. For cooling to zero from this amount, energy will be spent:
Q2 = C * m * (4 – 0);
Q2 = 4C * m;
Q3 = E – Q2 = A * M;
5. From here we find the mass of ice:
M = (E – Q2) / A;
M = (3600 * P – 4 * C * m) / A;
M = (3600 * C * m * dT / t – 4 * C * m) / A;
M = C * m * (3600 * dT / t – 4) / A;
M = C * m * (3600 * (16 – 4) / 1200 – 4) / A;
M = 32 * C * m * / A.
Answer: M = 32 * C * m * / A.