• ## Discover

1. Home >
2. All Categories >
3. Science & Mathematics >
4. Mathematics >
5. Resolved Question
Member since:
10 March 2008
Total points:
247 (Level 1)

## Resolved Question

Show me another »

A hollow square - shaped tube open at both ends is made of iron. The internal square is of 5cm side and the length of the tube is 8 cm. There are 192 cm^3 of iron in this tube.Find its thickness.

by Jerome J
Member since:
04 October 2008
Total points:
80,776 (Level 7)

## Best Answer - Chosen by Voters

Cross-sectional area of iron tube = 192 cm³ / 8 cm = 24 cm²
A = s² - 5² = 24 cm²
s² = 25 + 24 = 49 cm²
s = √(49 cm²) = 7 cm
thickness = ½(7 - 5) = 1 cm

There are currently no comments for this question.

• by dcno02
Member since:
25 August 2008
Total points:
11,304 (Level 6)
Let x be the length of the external square.

(x^2 - 5^2) * 8 = 192
• Member since:
28 November 2008
Total points:
3,361 (Level 4)
You multiply five with five and then add 192 then subtract with the answer of 5X5+(192divided by8) YOU WILL get some thing and find our the percentage of the same You will get something That is NOT the answer.
20% 1 Vote
• by vatchen
Member since:
26 September 2008
Total points:
124 (Level 1)
total volume of shape=192 cm^3 = cross section surface x Length
Length = 8 cm
cross section surface = total area - inner area (hollow part)
inner area side = 5 cm
total area side = x
cross section surface = x^2 - (5x5)

192 = (x^2 - (5x5)) x 8
x^2 = 192/8 +5x5

x= 7 cm

thickness t
t = (7-5)/2
t=1 cm

### Source(s):

basic calculus
20% 1 Vote
Member since:
26 July 2008
Total points:
1,594 (Level 3)
Volume = area of cross section * length
192 = (x^2 - 5^2) 8
24 = x^2 - 25
x^2 = 49
x = 7 cm
x-5 = 2
This length is twice the thickness.
2/2 = 1 cm
20% 1 Vote