Answer:
D
Explanation:
cuz it transforms from one to another can't be created not destroyed.PERIOD!
The answer is a.12.5kg because i just did the test and it was correct.
hope this helps
We can solve the problem by using the first law of thermodynamics:

where
is the variation of internal energy of the system
Q is the heat added to the system
W is the work done by the system
In this problem, the variation of internal energy of the system is

While the heat added to the system is

therefore, the work done by the system is

Answer:
changing the direction in which a force is exerted
I think it's 3. within an outer arm