Answer:
If you have two batteries and they have precisely the same voltage then placing one backwards will effectively cancel out the voltages and no current will flow. However, batteries aren't like that. The slightest difference in voltages mean that current will flow.
Explanation:
Answer:
The branch of applied mathematics dealing with motion and forces producing motion is called mechanics.
A perfect machine is not possible because perfect machines mean that the system will always perform at a 100% efficiency, and that's not possible in real life because the systems of the real world will always lose some energy in the form of heat, resulting in a lower efficiency percentage.