act upon vs impel

act upon

verb
  • To take action on the basis of information received or deduced. 

impel

verb
  • To urge a person; to press on; to incite to action or motion via intrinsic motivation. 

  • To drive forward; to propel an object, to provide an impetus for motion or action. 

How often have the words act upon and impel occurred in a corpus of books? (source: Google Ngram Viewer )