Part 2 of 2 - Let's build on yesterday's problem.
Why do we bother finding out how much something deforms, when it's stress that gives us a measure of whether something will fail?
In the real world, directly measuring stress can be pretty difficult. It's much easier to stick a strain gauge to the interested area of a part to measure the amount something deforms. From there we can use an equation to relate strain to stress. We go into this more in today's solution (after you try solving the problem of course!).
You hang a steel cylinder from the ceiling. At 3 various points, you decide to hang some heavy stuff. Young's Modulus of steel is 210 GPa.
How much will the length of the steel cylinder change?