What do 'horseradish' and 'horsepower' have to do with horses?

Horse radish is a very strong tasting food with a kick to it! So hence standing behind a horse will more than likely kick you. Horse power was invented before cars, however now a days when you hear the saying 'this car has 150 horse power' it means that it is pretty much like 150 horses strength, which is alot!
Hope this helped :)

Horseradish Has  Wicked Kick To It.. Like Standing Behind A Horse Which Is No No.  Horse Power On Trucks And Cars Refers To  How Much Power The Vehicle Has.. Several Hundred Horses Is Very Powerful.. I Guess.. Can't Use Mice Or Ants.. Would Not Sound Right To Say Mice Power Or Ant Radish. EWWW

Horse power eg 150 horse power engine =the power of 150 horses, horse radish well got a kick to it only a guess,

Horsepower has to do with horses because of the power or strength that horses can have but horse radish baffles me too.

Mainly I believe this question has been answered by all of the above, but I could venture a guess that horseradish is like a radish with a lot of horsepower!  Hehe