Max has 100 square inches of aluminum with which to make a closed cylinder. If the radius of the cylinder must be 2 inches. How tall will the cylinder be?

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Answer 1 · 2018-05-25T14:48:11

#(50 - 4pi)/(π) =h ~~ 11.92 "inches"#

Formula for the surface of a closed cylinder is:

#A_"surface" = 2pir^2 + 2πrh#

so yours is:

#A = 100#

#r=2#

Solve:

#100 = 2π2^2 + 2πh#

#100 - 2π4 = 2πh#

#(100 - 8pi)/(2π) =h#

#(2(50 - 4pi))/(2π) =h#

#(50 - 4pi)/(π) =h#

#(50 - 4pi)/(π) =h ~~ 11.92 "inches"#