Need Engineering Help

Well it has been a long time since I have taken a class going over this and am looking for a little help. I am trying to find the tension in each cable. My cousin was asking me about it and I just can't remember for anything. Each Circle is a Pulley.

 

I know someone on here must know something about engineering... if nothing else I am going to see if I can dust off some of my old books and flip thru them.

 

haha yea I am trying to get some young buck though... figure they are still in classes

 

I know this is a statics problem, so all the forces are equal. The lengths of the ropes don't really matter since they are considered weightless.

Tension of Cable 3 (L3) is just the weight.
Ft3=60lbs.

Tension of Cable 2 (L2) is done by setting up a right triangle to get the tension force at that angle. So Cos(180-theta1)=Wt/Ft2==>Ft2=60/Cos(42.4deg)=81.25lbs tension for Length 2.
Ft2=81.25lbs

Tension in cable 3 is still 60 lbs down, and found by using the theta2 and using it to get another right triangle with cable 3 to get equilibrium (I think). cos(15.6)=60/Ft1==>Ft1=60/cos(15.6)=62.29lbs
Ft1=62.29lbs

(It's been 6 years since I've had this class, so better double check the answer)

 

summation of the forces. Find all the forces in the x and y direction, equate and set each equal to zero.

 

my bad, i thought they said t1, t2, t3. not lengths.

 

Thats right, hopefully I did it correctly above.

 

That seems correct... It has been so long since I have even worked a statics problem lol

 

If the pulleys are frictionless, the tension is the same trough the whole cable.

 

I took statics last semester so I should know how to do this.

Unfortunately I slept thru half of my classes, so I don't know how to do this.

 

I didn't know how to do statics til I got threw dynmaics.

 

yeah, all I know is EF=0 and EM=0.

How you get to that I have noooooooooooo idea haha.

 

haha I take statics next quarter. At my school its an 80% fail rate

 

I still say its the same tension ( L1=L2=L3 ) those are fixed pulleys, frictionless with a cable with negligible mass.

 

Have fun!

I took it twice. First time was with this teacher that gave really fucking complicated problems and couldn't teach for shit. I dropped the class immediately after taking the 2nd test (literally, once I got back to my room I dropped it haha.) I picked up a different teacher for my send hack at the class. At least 60% of the class was people that had the guy I had for my first whack at the class.

 

x2
Those pulleys are changing direction of force and not multiplying it so T1=T2=T3.