add ? J of heat 2 raise temp of 100 grams of H2O by 10 degrees C?

Answer 1

Definition: 1 cal is the amount of heat (energy) to raise temp of 1 g of water by 1 oC.
Therefore to raise temp of 100 g of water by 10 oC you need 1000 cal.
By another definition 1 cal = 4.186 J. Therefore you will need 4186 J.