Weight - Wrought Iron

[Guest]

A wrought iron bar has the following dimensions:

1 square inch area of cross section.

1 yard in length.

Determine weight of bar.


Check my calculations:

Wrought iron weighs .28 lbs. per cu. inch.

Specific gravity of wrought iron - 7.78

1 x 1 x 36 = 36 cu. inches.

36 x .28 = 10.08 lbs.

1 x 1 x 36 = 36 cu. inches.

Weight of cu. in. of water - .2833 lbs.

Weight of cu. in. of wrought iron - .2833 x 7.78 = 2.204074 lbs.

Weight of bar - 36 x 2.204074 = 280.08 lbs.

Where did I make the error(s) ?

[Guest]

Determine weight of bar.

Wrought iron weighs .28 lbs. per cu. inch.

1 x 1 x 36 = 36 cu. inches.

36 x .28 = 10.08 lbs.

Just stop here......

Do no more calculations

....................Simple................

[Guest]

Where did I make the error(s) on the second calculation ?

Just curious.

[Guest]

Your error is doing this calculation
It is not needed.........

Specific gravity of wrought iron - 7.78..xxxxxyou don't need this...this relates the weight of water to weight of iron
You were given the density of iron as .27 lbs per cu. in. of iron directly. no need to convert

1 x 1 x 36 = 36 cu. inches.

Weight of cu. in. of water - .2833 lbs. XXXXX this is the weight of 1 cu. in. of iron.

Weight of cu. in. of wrought iron - .2833 x 7.78 = 2.204074 lbs.xxxx no

Weight of bar - 36 x 2.204074 = 280.08 lbs.xxxx no

Where did I make the error(s) ?

[Guest]

Thanks for info ...