Explanation:
The magnetic needle of a compass lines up with Earth's magnetic poles.
D. Destructive interference. An easy way to think about it is the waves are opposite each other, so they essentially cancel each other out, or make an effort to.
1 horsepower is equal to 746 W, so the power of the engine is

The power is also defined as the energy E per unit of time t:

Where the energy corresponds to the work done by the engine, which is

. Re-arranging the formula, we can calculate the time t needed to do this amount of work:
Answer:
<u><em>Part A:</em></u>
They will repel each other because same poles repel each other.
<u><em>Part B)</em></u>
They will attract each other because different poles attract each other..