horsepower vs impact

horsepower

noun
  • Strength. 

  • Power derived from the motion of a horse. 

  • A nonmetric unit of power (symbol hp) with various definitions, for different applications. The most common of them is probably the mechanical horsepower, approximately equal to 745.7 watts. 

  • A metric unit (symbol often PS from the German abbreviation), approximately equal to 735.5 watts. 

impact

noun
  • The force or energy of a collision of two objects. 

  • A significant or strong influence or effect. 

  • A forced impinging. 

  • The striking of one body against another; collision. 

verb
  • To stamp or impress onto something. 

  • To collide or strike, the act of impinging. 

  • To significantly or strongly influence or affect; to have an impact on. 

  • To compress; to compact; to press into something or pack together. 

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