- #1
Alison A.
- 86
- 2
Homework Statement
Blocks A and B each weight 170 lb and rest on frictionless surfaces. They are connected to one another by cable AB. Determine the force P required to hold the blocks in the equilibrium position shown and the reactions between the blocks and surfaces.
Hint given: This problems requires two separate FBDs of blocks A and B. Isolating each block requires a closed surface that passes through the cable and the smooth surface on which it's resting. Examine block A first to determine the cable tension required to keep it in equilibrium. You can then use this information to determine the required force P to keep block B in equilibrium.
Image attached as well as free body diagram:
http://imgur.com/a/FV3NJ
Homework Equations
ΣFx=0
ΣFy=0
Basic trig
The Attempt at a Solution
I drew both force diagrams like the hint suggested and then started to try to find ΣFx and ∑Fy for block A and I don't think I got very far since my numbers do not seem correct (you can see in the picture). I know I need to find tension on block A then from there use that to find P, however I don't know where the angle of block B fits in. In order to keep block B in equilibrium P has to cancel out an Fx components. Just a little stuck on getting there...