7. higher order thinking the cylinder shown is a steel tube that weighs 0.2835 pound per cubic inch. the…

7. higher order thinking the cylinder shown is a steel tube that weighs 0.2835 pound per cubic inch. the inner part of the tube is hollow. what is the weight of the tube? use 3.14 for π, and round to the nearest tenth.
Answer
Explanation:
Step1: Calculate outer - radius and inner - radius
Outer diameter is 5 in, so outer radius $R=\frac{5}{2}=2.5$ in. Inner diameter is $2\frac{3}{4}=\frac{11}{4}$ in, so inner radius $r = \frac{11}{8}=1.375$ in. Length of cylinder $h = 8\frac{3}{4}=\frac{35}{4}$ in.
Step2: Calculate volume of the tube
Volume of a hollow - cylinder $V=\pi h(R^{2}-r^{2})$. Substitute $\pi = 3.14$, $h=\frac{35}{4}$, $R = 2.5$, and $r = 1.375$ into the formula. $V=3.14\times\frac{35}{4}\times(2.5^{2}-1.375^{2})$ First, calculate $2.5^{2}=6.25$ and $1.375^{2}=1.890625$. Then $2.5^{2}-1.375^{2}=6.25 - 1.890625 = 4.359375$. $V=3.14\times\frac{35}{4}\times4.359375$ $V = 3.14\times38.206640625=120.0698416$ in³.
Step3: Calculate weight of the tube
Weight per cubic - inch is 0.2835 pound. So weight $W=0.2835\times V$. $W=0.2835\times120.0698416\approx34.0$ pounds.
Answer:
34.0 pounds