00:01
In this problem we have a bar that's pinned at its middle, that's uniform, and then it's supported by a spring on the left end.
00:12
So we can draw a free bi diagram of the bar, so we have a reaction forces here, the force from the spring here.
00:20
Then we have fruit by diagram of the spring, the force acting from the body on the spring, and then the equal and opposite force on the other side of the spring.
00:29
Again, i'm using small angles here.
00:34
So the displacement at this point here, i think i forgot to divide by 2.
00:45
So the displacement at this point here, so this distance is l over 2.
00:50
It should really be l over 2 sine theta, but since theta is small, we're going to replace sine theta with theta.
00:58
So this displacement is l over 2 sine theta...