Question

A cup of hot water loses 265 cal

Answer 1

Answer:

-1071 Joules

Explanation:

The Joule was introduced as the SI unit for energy in 1925.  One calorie is equal to approximately 4.184 joules(J).  This is a conversion factor that we can write two ways:

(1cal/4.184J) or (4.184J/1cal)

(265 cal)*(4.184J/1cal) = 1071 J

Since the energy is leaving the system, it should be written with a minus sign:  -1071J