A 50 gram glass holds 400 grams of liquid water and 75 grams of ice. After 20 minutes the mass of ice is 50 grams. In 1-2 sentences, assuming no evaporation or sublimation has occurred, calculate the mass of the liquid water at this time and explain how this is found.

Answer 1

Initially, there are 400 grams of liquid water and 75 grams of ice. After 20 minutes, if the mass of ice is now 50 grams, that means 25 grams of ice has melted into water. Since no evaporation or sublimation has occurred, the total mass of liquid water at this time is the initial mass of liquid water (400 grams) plus the mass of melted ice (25 grams), resulting in a total of 425 grams of liquid water.