Q.1. A child complains that her milk is too hot. It is indeed too hot at 90o C. Her mother pours 70 g of cold milk at 7o C to the 180 g milk already in the cup. If the specific heart capacity of milk is 3700 J.kg-1.K-1, what is the temperature of mixture now?
2. Throughout a nuclear reactor accident, 570 m3 of water at 20o C is pumped into the reactor core which is producing heat at the rate of 250 MW. If the water is allowed to boil at normal atmospheric pressure how long would it take to boil away all this water?
3. 600 J of work is prepared to compress a given mass of gas isothermally to half its initial volume. How much work is necessary to compress the similar amount of gas isothermally to 20th of its original volume?