00:01
Determine the reactions at the beam support for the load shown.
00:06
So here we have a beam, a d, that is being supported by two pins at b and at c.
00:14
So b is technically a onomal pin which can provide a horizontal and vertical reactor force.
00:21
And c is a roller pin when you can only provide a vertical reaction force.
00:29
I'll call this force c.
00:30
But because we have no other horizontal force, bx here has to be zero.
00:34
So we only have one reaction force at b, along the y direction.
00:39
So let's draw our coordinate system as normal.
00:43
And now to determine our reactions b and c, we need to determine the total load supplied to our beam.
00:53
So here we have a triangular load with a peak at 480 pounds per feet.
01:03
This will correspond to a load of 480 times 3 feet divided by 2.
01:10
The area of a triangle, corresponding to 720 pounds.
01:20
We're going to the same thing in this direction, or in this segment here, where the maximum load is 600 feet.
01:28
So let's compute 600 times the base length here of 6 feet and divided by 2.
01:35
1 ,800 pounds.
01:38
And lastly, midway point c and d, we have 600 pounds over 2 feet, a uniform distributed load.
01:52
Now let's look at the sums of our forces...