A plumbing firm is required to make a copper cylinder of 115 litres capacity to fit into a smaller than usual airing cupboard in which the max diameter is the cylindermust not exceed 425mm. How high will the cylinder need to be?
I don't know exactly what an airing cupboard means, but if I understand the problem, then it is just about volumes of cylinders.
V = pi(r^2)h
r = (425mm)/2 = 212.5 mm = 21.25 cm. maximum
V = 115 liters = 115,000 cu.cm.
So,
V = pi(21.25^2)h = 115,000
h = 115,000 / (pi *(21.25^2)
h = 81.064 cm = 810.64 mm high or lower. -----------answer.