00:02
So in this problem, we have a brass rod, and we are trying to find the change in the length of the brass rod.
00:13
And so this is the diagram given approximately, and so we have a series of three forces being applied on our rod at different locations.
00:22
So first let's write down our expression for, i guess, change in length, deformation.
00:30
So delta l is equal to force times the length of that, length of that particular segment where the force is being applied over the cross -sectional area times young's modulus.
00:48
And so another given in the problem is that the area is equal to 250 millimeters squared.
00:58
So now we're going to apply this formula for different segments within our brass.
01:04
Rod.
01:07
So we can say that the total deformation, delta l, will be equal to delta l -a -b, so delta l -a -b being the section over here, plus our delta l -b -c, plus our delta l -cd.
01:32
So c -d will be the segment over here.
01:36
So now what we can do is write down on an expanded form of our expression, so we can say delta l -a -b is f -1 times l -a -b over a -e plus f -2 times l -b -c over a -e, plus f -3, l -c -d over a -e.
02:13
So notice that all these forces are actually different.
02:17
We have an f -1.
02:18
F2 and f3...