Question

in 11-16, apply the formula for surface area of a cylinder s

1. julia uses cardboard tubes to ship the art she sells online. how much cardboard does she need to make each tube? use 3.14 for $pi$.

13 in.
3 in.

Explanation:

Step1: Identify given values

Diameter $d=3$ in, height $h=13$ in, $\pi=3.14$
Radius $r=\frac{d}{2}=\frac{3}{2}=1.5$ in

Step2: Recall tube surface area formula

A shipping tube has 2 circular ends + lateral surface area:
$SA = 2\pi r^2 + 2\pi r h$

Step3: Calculate area of circular ends

$2\pi r^2 = 2\times3.14\times(1.5)^2 = 2\times3.14\times2.25 = 14.13$ in²

Step4: Calculate lateral surface area

$2\pi r h = 2\times3.14\times1.5\times13 = 3.14\times39 = 122.46$ in²

Step5: Sum the two areas

$SA = 14.13 + 122.46$

Answer:

136.59 square inches