# Help with pulley problem with sag

1. Sep 18, 2009

### mike41

1. The problem statement, all variables and given/known data

If the 1.5 kg block is suspended from the pulley B and the sag of the cord is d = 0.15m, determine the force in cord ABC. Neglect the size of the pulley

3. The attempt at a solution

They dont even give an angle, im not sure how im supposed to do this.

2. Sep 18, 2009

### rl.bhat

Draw a perpendicular from BD on AC. That bisects AC.
In triage BDC you can all the three sides.So fond the angles.

3. Sep 18, 2009

### mike41

so for the angle i got 53.3 degrees. Tan^-1(0.2/0.15) = 53.3 degrees

Force x y
AB -ABsin53.3 ABcos53.3
CB CBsin53.3 CBcos53.3
14.715N 0 -14.715

X axis = 0 N

CBsin53.3 - ABsin53.3= 0

y axis = 17.715 N

CBcos53.3 + ABcos53.3 = 14.715 N

so then i substituted for CB = ([14.715 / cos53.3] - AB)
= 24.62

and got 12.3 as the tension total. thankyou
i was confused by how the lines in the diagram are different sizes and did not think that the pulley would be in the center with a diagram like that