A cup holds $0.25\,\text{kg}$ of water at $60\,^{\circ}\text{C}$. After some time, the water cools down to $20\,^{\circ}\text{C}$. What amount of energy is transferred from the water to the surroundings? (The specific heat capacity of water is $4200\,\text{J}\,/(\text{kg}\,^{\circ}\text{C})$.)
- A$21000\,\text{J}$
- B$42000\,\text{J}$
- C$63000\,\text{J}$
- D$84000\,\text{J}$