# Math Help - shear stress calculation help

1. ## shear stress calculation help

hi i was wondering if osmeone could help with the following question?

The shear stress, t, across the wall of a thin walled tube is proportional to the applied torque, T, inversely proprortional to the square of the mean radius, r, of the tube and inversely proprtional to the thickness of the wall of the tube, t.

given the following dat, determine the law of proportionality:

t=30000kPa T= 3620 Nm
r= 80mm t=3mm

determine the shear stress, correct to three significant figures, across the wall of the tube when the applied torque is 5000Nm
thanks

2. Originally Posted by paulhr1976
hi i was wondering if osmeone could help with the following question?

The shear stress, t, across the wall of a thin walled tube is proportional to the applied torque, T, inversely proprortional to the square of the mean radius, r, of the tube and inversely proprtional to the thickness of the wall of the tube, t.

given the following dat, determine the law of proportionality:

t=30000kPa T= 3620 Nm
r= 80mm t=3mm

determine the shear stress, correct to three significant figures, across the wall of the tube when the applied torque is 5000Nm
thanks
Lol this is the STATISTICS and probability forum, not the Statics forum lol.

Anyway, if it's proportional to those things in that manner then you can conclude that:

$\tau = \frac{kT}{\bar{r}{t}}$

Where k is the constant of proportionality. You have to find out what k is by sticking those numbers in to solve for k. Once you have it, you can use the full equation to work out what the shear stress is when T = 5000Nm.