A gallon of paint covers 20 ft2 of surface area. how many revolutions can an 8 in. wide paint roller with a diameter of 3 in. make before using up a 5-gal can of paint?
we first compute for the surface area of the roller and the total area covered by the 5 gal paint 1gal = 20 ft2 5 gal = 20ft2 x 5 = 100ft2 1 rev = surface area of the side of the cylinder 1 rev= 2pirh where radius= 1.5 in=0.125 ft h= 8 in=0.67 ft 1 rev= 0.53 ft2 5 gal = 100ft2 total revolutions = 100ft2/0.53ft2 total revolutions = 188.68 revoluions A 5 gal paint can take 188.68 revolutions of paint roller with 8in wide and diameter of 3 in.
