00:01
And this problem, we have a fairly complicated mechanism that's a relay.
00:06
So we have, but it's fairly simple mechanically.
00:11
We have this lever arm here that's attached to a pivot and held supported by a spring, and then there's a contact up here.
00:19
And so then we have a solenoid down here that when energized will pull this lever away from the contact, thus breaking the circuit.
00:30
What we have here is a pivot force, and i'll call that one, and then say that is the origin at a pivot point.
00:39
We have the spring force here at a distance of 30 millimeters in this direction from the origin.
00:45
We have the contact force, which we're told initially, well, initially is given, and we want to try to figure out what the force in the spring is if this is 0 .4 newton's.
01:01
And that is 100 millimeters from the pivot in this direction.
01:06
So now we have all of our forces and position vectors, and we can just some forces and moments again.
01:15
And really all we needed to do was some moments in this case about this point, because that will give us all the information we needed, which was f...