What's the difference between compel and impel?

For example in: I could compel/impel my brother to give me the money.

Does compel always mean "with force"? What's more common in English?

Thanks in advance 😊
Best wishes
Michael

Question

What's the difference between compel and impel?

For example in: I could compel/impel my brother to give me the money.

Does compel always mean "with force"? What's more common in English?

Thanks in advance 😊
Best wishes
Michael

Answer

Compel = to force 
Impel = to incite someone, e.g Martin Luther King s speech went towards someone 's heart to move doing something.