Had bluffs been included in the system then a separate account for chemical energy ech would need to shown on energy bars charts with two or more in the initial state than in final state

during a change. The initial energy state of a system is represented with a bar graph showing the amount of energy stored in each account (or storage mode). To the right of the bar graph, an energy flow diagram indicates which items are inside and outside of the system and whether energy is transferred into or out of the system by working or heating. Finally, to the right of the energy flow diagram, another bar graph indicates the final distribution of energy stored within the system. To use the representation for quantitative analysis, a mathematical expression or energy value can be written below each bar and the energy flow diagram. The sum of the initial stored energy in the system plus or minus any energy flowing in or out of the system equals the sum of the final stored energy in the system. Consider the example below in which a water balloon tossed by Buffy lands and bursts on Biff's head. Initial Final beOI'B throw balloon hits Biff