00:01
Yeah, um, this problem.
00:02
We're presented with a brass broad of a certain length and diameter.
00:07
Um, it goes through a temperature change and were asked what what force is needed to keep the bar contracting.
00:15
So this is a thermal stress problem and are relevant.
00:18
Equation is force over.
00:22
A cross sectional area equals the opposite of illness.
00:28
Module s for whatever material times, the coefficient of linear expansion times change in temperature.
00:37
So let's make sure this is the equation for us.
00:41
You have force.
00:44
That's what we're looking for.
00:45
So it better be in the equation.
00:48
Cross sectional area.
00:50
Um, we're not giving this, but were given the diameter so we can easily find that young's modu elice.
00:58
Um, that's based on the material.
01:01
We're told it's a brass rod so we can or you can look up the youngest module iss in a table in your physics textbook.
01:10
Same with the coefficient for linear expansion.
01:15
Uh, change in temperature.
01:18
We don't have what we do have the final and initial temperatures.
01:21
So, uh, that's that's easy to find.
01:26
Okay, so let's start finding our values, politicians.
01:39
So for our area circle.
01:44
So it's high r squared where r is the radius and radius is half the diameter and they give us a diameter of, um, 1.6 centimeters.
02:10
But we're gonna want to change that, um, 2 m, because that their standard units and it's just gonna make our life easier.
02:23
Let's point out 16 m, times two e divided by two.
02:33
I'm just gonna be zero point 00 each meters...