# Calculating size of rectangle cross section

## Homework Statement

A cmedium carbon steel rod has a rectangular cross section and must cope with a tension of 29 430 Newtons . The thickness of the rod is 15 mm calculate the siz of the cross section?

## Homework Equations

A=P/Ok

3. The Attempt at a Solution [/b

O = UTS = 750 Mpa k = 0.25 P = 29 430 N t = 15 mm

A= P/Ok

29 430 / 200 = 187.50 mm^2

187.5 / t = 187.5 / 15 = 12.5 sqrt = 3.5355

Size of cross section = 12.5 mm x 3.5 mm

I believe I have the area correct but not sure if the sides are correct ?

nvn
Homework Helper
rad10k: Your answer is currently incorrect. Check your math. MPa should be spelled MPa, not Mpa. The name Newton is the name of a man, whereas newton (N) is a unit of force. Also, place a comma between separate equations on the same line, for clarity. Try again.

ok thanks

A=P/Ok

750 * 0.25 = 187.5, 29 430 / 187.5 = 156.96

Area = 156.96 mm^2 from this;

A/t sqrt = 156.96 / 15 = 10.464, sqrt = 3.2348

size of cross sectional area is 10.4 mm x 3.2 mm

nvn
Homework Helper
rad10k: You should not perform sqrt.

so the cross section is 15 mm x 10.4 mm ?

nvn