00:01
In this problem, we're trying to find young's modulus, which can be expressed as the initial length of the object times the perpendicular force, divided by the cross -sectional area, times the change in length under the force.
00:17
So in this problem, we have a radius of the rope of 3 .5 millimeters.
00:23
This is just divided by two, since they give us the diameter.
00:26
So this is the radius.
00:28
But we need to convert this into meters.
00:30
And so when we do that we get 3 .5 times 10 to minus third meters.
00:36
Now that we have a radius in meters, we can figure out what the area in meter squared is.
00:41
So the area is piar squared.
00:44
We're assuming that the cross section of this thing is a circle, and so that's the area.
00:49
And so plugging in this, we get 3 .85 times 10 to the minus 5.
00:55
This is now a meter squared since we've got meters here for the radius...