00:01
In this question, we have a steel ring that wants to slip into a brush shaft, but to do that, we need to heat it up so it goes into linear dilettation.
00:14
So this is the first part, so let's do this.
00:18
So in general, object, when it's heated, we have a difference in length.
00:27
So alpha, l0, delta, t.
00:34
We know the initial value for the diameter of the steel ring.
00:38
We just need to make that the final value be exactly equal to the brush shaft, so the steering can slip through.
00:49
This is easy to do.
00:51
Let's write this as delta t is equal delta l divided by alpha of the steel l0.
01:02
We have everything that we want here, so we can write here.
01:07
So this is 0 .020 divided by alpha s is the linear coefficient of dilatation for the steel.
01:20
This is 1 .2 times 10 to the minus 5.
01:26
And l0 is the initial size.
01:29
This is 2...