Why is the joule, the SI unit of energy, also the appropriate unit for measuring heat?
1 Joule = 1
The definition of work is a force acting over a distance.
=> Work = Force x Distance = F x d
From Newton's 2nd Law of Motion, Force = Mass x Acceleration
=> F = m x a
Substituting m x a for F in the Work formula => Work = m x a x d
The SI Unit for mass =
Substituting into Work = mass x acceleration x distance
The other unit for heat quantities is the 'scientific calorie', or calorie (c) ; not to be confused with the neutritional calorie (C) (= 1000 scientific calories, or 1 Kilocalorie). The relationship between the two energy terms is as follows ...
1 calorie = 4.184 joules