What is the mass of water if it took 336,000 J of energy to heat it by 40 degrees?

The amount of heat spent on heating the body or released during its cooling is equal to the product of the specific heat capacity of the substance, body weight and the difference between the final and initial temperatures.
Q = c * m * ΔT
Here Q is the amount of heat, c is the specific heat capacity of the substance that makes up the body, m is the mass of the body, –ΔT is the temperature difference.
m = Q / c * ΔT = 336000/40 * 4200 = 2 kg;
Answer` 2 kg;