Paint spray gun works on the principle of Bernoulli’s theorem.
Bernoulli’s theorem states that the total mechanical energy of the moving fluid comprising the gravitational potential energy of elevation, the energy associated with the fluid pressure, and the kinetic energy of the fluid motion, remains constant.
When the piston is moved, high-speed air is passed over the tube which is dipped in a liquid that needs to be sprayed. There is a creation of low pressure over the tube because of high-speed air so that the liquid rises into the tube and is then blown off in small droplets with expelled air.
Venturimeter, working of an aeroplane, and working of lift are some the other applications of Bernoulli’s theorem.