Question

why doesn't cold water boil faster than hot water?

Answer 1

Cold water will require more amount of time to boil than the hot water

Reason: For increasing the temperature of 1C of 1g of water, we need 4.184J of heat (specific capacity of water)

Since the temperature of cold water < temperature of hot water and boiling will start at 100C

Hence more heat needs to be pumped to cold water in order to make it temperature increase to boiling point. Assuming the heat source to be same and the quantity of water as same, the time taken by cold water will be higher than hot water