# Wire Length

Algebra

### Wire Length

A coil of steel wire is 0.025 in. in diameter, and weighs 50 lbs. Steel weighs .29 lbs. / cu. ft. Find weight of the coil.

The wire is a cylinder.

Volume = Pi * r^2 * h.

3.1416 * 0.0125 * 0.0125 * h

Unsure how to proceed.
Guest

### Re: Wire Length

Good morning!

$$m=50lbs\\ d=\frac{m}{V}\\ 0,29=\frac{50}{V}\\ V=\frac{50}{0,29}\\ \pi\cdot R^2\cdot H=\frac{50}{0,29}\\ \pi\cdot\left(\frac{D}{2}\right)^2\cdot H=\frac{50}{0,29}\\ \pi\cdot\left(\frac{\frac{0,025}{12}}{2}\right)^2\cdot H=\frac{50}{0,29}\\ \pi\cdot\left(\frac{0,025}{24}\right)^2\cdot H=\frac{50}{0,29}\\ H=\frac{50\cdot 24^2}{0,29\cdot\pi\cdot 0,025^2}\\ H\approx 50\,578\,343,29ft$$

Why such a long wire? Almost 9600 miles! Baltuilhe

Posts: 74
Joined: Fri Dec 14, 2018 3:55 pm
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### Re: Wire Length

Good Morning!

Answer they gave: 29,270 ft. (nearly).

Thanks.
Guest

### Re: Wire Length

The directions are "find the weight of the coil"!

It's 50 pounds!

HallsofIvy

Posts: 318
Joined: Sat Mar 02, 2019 9:45 am
Reputation: 108

### Re: Wire Length

It should read: Find the length of the coil.

Weight was a typo. My apology.
Guest

### Re: Wire Length

Also, another typo:

The .29 is lbs. / cu. in., not cu. ft.

My apology, again.
Guest