A piece of hot copper at `100^(@)`C is plunged into a pond at `30^(@)`C. The copper cools down to `30^(@)`C, while the pond, being huge, stays at its initial temperature. Then-

100 g of a copper body take at 60^(@)C is cooled to 40^(@)C. How much heat does it release ?

A body at 50^(@)C cools in a surroundings maintained at 30^(@)C . The temperature at which the rate of cooling is half that of the beginning is

A body at 50^(@) C cools in a surroundings maintained at 30^(@) C. The temperature at which the rate of cooling is half that of the begining is

A body at 80" "^(@)C cools down to 64" "^(@)C in 5 minutes, and in 10 minutes it cools down to 52" "^(@)C . What will be its temperature after 20 minutes ? What is the temperature of the environment ?

A body at 50^(@)C cools in a surroundings maintained at 30^(@)C The temperature at which the rate of cooling is half that of the beginning is .

Water of mass 200 g and temperature 30^(@)C is taken in a copper calorimeter of mass 50g and temperature 30^(@)C . A copper sphere of mass 100g and temperature 100^(@)C is released into it. What will be the maximum temperature of the mixture ? [ c ( water = 1 cal //g.^(@) C , c ( copper ) = 0.1 cal//g.^(@)C ]

A copper calorimeter, blackened outside, is filled with some hot liquid and placed on a table. It is found to cool from 60^(@)C to 50^(@)C in 4 minutes and 40^(@)C to 30^(@)C in 8 minutes. What is the temperature of the surroundings? Why is blackened?

A liquid initially contracts when cooled down to 4^(@)C but on further cooling down to 0^(@)C , it expands. The liquid is :

A copper ball cools from 62^(@) C , C to 50^(@) C in 10 minutes and to 42^(@) C ill the next 1 Ominutes. Calculate its temperature at the end of allother 10 minutes.