Do firefighters like these (view hi-res image) need to know physics? Here are some related questions:
How does water put out a fire?
How much pressure should there be in the hose?
And why cut a hole in a house on fire?
To find out how physics provides the answers, see Robert Egler's article "The Physics of Firefighting," on page 599 of the December 1990 issue of "The Physics Teacher", a publication of the American Association of Physics Teachers.