Thread: maximization question

a plumbing firm is required to make a copper cylinder of 155 litres capacity to fit into a smaller than usual airing cupboard in which the diameter of the cylinder must not exceed 425mm. how high will the cylinder need to be?

Originally Posted by zak_killcity14@hotmail.co

a plumbing firm is required to make a copper cylinder of 155 litres capacity to fit into a smaller than usual airing cupboard in which the diameter of the cylinder must not exceed 425mm. how high will the cylinder need to be?

For a cylinder:
V = (pi)r^2*h = (pi)(d/2)^2*h = (pi/4)d^2*h

You've got V, you've got a maximum d, so solve for h.

-Dan