00:02
In this problem, we're given the diagram of a traffic signal, and we need to find out the tension in the left bolt, which i've labeled as bolt a.
00:19
So first off, let's think about this problem a little bit.
00:27
So we're given an entire elaborate structure, and we're given the distances from the center line of the bowl, and we need to find out the tension.
00:39
On one of these rings.
00:40
So let's just first draw out all the forces.
00:45
So there's a force that is equal to the weight of the connecting rod.
00:50
Let's call it w sub r.
00:53
There's the weight of the traffic signal.
00:55
Let's call it w sub t.
00:57
And there's the weight of the bowl.
01:01
Let's call it w sub b.
01:07
There is a tension in both exerted by both of these bolts.
01:14
Now to solve for t sub a, we can take the torque about b.
01:23
So taking the torque about b, sigma tau, b.
01:31
So conventionally, any clockwise torques, clocks going this way are negative, and any anti -clockwise torques, so torques going this way, are positive.
01:47
So that gives us the total torque as, first let's consider the positive torque...