We can calculate the percent change by calculating:
[tex]\text{ \%change}=\frac{\text{ final state-initial state}}{\text{ initial state}}\cdot100\text{ \%}[/tex]
In this case, the initial state is 120 degrees and the final state is 100 degrees.
Then, we can calculate:
[tex]\frac{100-120}{120}=-\frac{20}{120}\approx-0.167=-17\text{ \%}[/tex]
The percent change is approximately 17% (negative).
