energetic vs hard at work

energetic

adj
  • Characterised by force or vigour; full of energy; lively, vigorous. 

  • Possessing or pertaining to energy. 

noun
  • Any material utilized for its release of energy, either as an explosive, propellant, or for pyrotechnic effects. 

hard at work

prep
  • Labouring with great effort and diligence; working hard. 

How often have the words energetic and hard at work occurred in a corpus of books? (source: Google Ngram Viewer )