00:01
We'd like to find our reactions at point a, b, and c.
00:05
So let's take a look first at our, we can use la mies theorem.
00:12
Let's first draw a free body diagram.
00:14
We have our reaction at d, reaction at a, where this is 60 degrees, this is 30 degrees, and this is our 700.
00:25
So we can say 700 divided by sine of 90 is equal to ra, divided by sine of 120 equal to r d divided by sign of 150 so we can use this to solve for r a so using this we have 700 times sine of 120 is equal to r a times sign of 90 so we divide both by sign of 90 to get r a so let's plug that into a calculator we have 700 times sign of 120 divided by sign of 90 gives us 606 .2 newtons for a reaction at a.
01:12
Now we can use this to find reaction at d as well.
01:16
So we can write 700 times sine of 150 degrees is equal to r at d times sign of 90 degrees.
01:26
So rd is 700 times sign of 150 divided by sign of 90, which is 350 newtons.
01:36
So there we found two of our reactions already...