00:01
For this problem on the topic of equilibrium and elasticity, we are given four bricks each of length l, which are all identical and uniform.
00:09
They are stacked in two different ways on a table, and we want to maximize the overhang distance h in each of the arrangements.
00:17
We want to find the optimum distances a1, a2, b1 and b2, as well as calculate the overhang distance h for each of the arrangements.
00:26
So we locate the origin of the x -axis at the edge of the table and choose the right direction to be positive.
00:33
In part a, the criterion is that the center of mass of the block above another must be no further than the edge of the one below.
00:42
Now, since the edge of the table corresponds to x is equal to 0, then the total center of mass of the blocks must be 0.
00:49
So we can treat the system in a as that of three items, one on the upper left, composed of two bricks, one directly on top of each other, with the mass 2m, and their center is above the left, edge of the bottom brick, a single brick at the upper right mass of mass m, which has its center over the right edge of the bottom brick.
01:11
So a1 necessarily is l over 2.
01:16
And the bottom brick has mass m...