If a question asks how much paint is required to coat the side of an oil-tank with 0.5 cm of paint. Tank has radius of 10 m and height of 3 m. It rests flat on its side.
2007-11-08 14:49:36 · 1 answers · asked by earthshake16 1 in Science & Mathematics ➔ Mathematics
I assume the tank is a right circular cylinder. I don't quite know what "rests flat on its side" means. I'm going to assume that all of the lateral surface area (that is, not the circular parts) is to be painted.
The volume of the tank is
V = π r² h
The painting amounts to increasing this volume slightly (but changing only r). Then
dV = (dV/dr) dr = 2π r h dr
dr is the thickness of the paint coat
Evaluate dV using the given tank dimensions (note that dr is given in cm; you'll want to convert this to meters). This is approximately equal to the volume of paint needed.
2007-11-08 15:30:31 · answer #1 · answered by Ron W 7 · 0⤊ 0⤋