# What must the resultant of the two tension forces in the ropes be?

1. Jan 22, 2008

### VanKwisH

1. The problem statement, all variables and given/known data
http://img251.imageshack.us/img251/3378/14906417xg0.th.png [Broken]
A) What must the resultant of the two tension forces in the ropes be?
B)What is the magnitude and direction of the tension in each of the two ropes?

2. Relevant equations

3. The attempt at a solution

For A .......... shouldn't the tensions in the ropes equal 500N?? cause they need to oppose the force of gravity on the load.........
and i have no idea where to start for B anyone know ??

Last edited by a moderator: May 3, 2017
2. Jan 22, 2008

### lukejian

for A, because it has 2 ropes, and they are not equal , so it's not 500N

3. Jan 22, 2008

### VanKwisH

ahhhh but what if it was one rope ???
also the rope connects to a central point which is the hook .......
so wouldn't the tension remain constant throughout the whole rope???

4. Jan 22, 2008

### lukejian

dont you see the hook is at the connecting point of 2 ropes?
the 2 ropes added up to 500N.
but then one rope is longer, and one is shorter, so the force they contain is different too

5. Jan 22, 2008

### VanKwisH

alright ........... the tensions are not equal ....... but they should add up to 500 N right??

Edit : Also for each tension ....... is it the overall tension ....... or the Y direction of the tensions??

6. Jan 22, 2008

### VanKwisH

bump.........

7. Jan 22, 2008

### awvvu

The tensions' y-components add up to 500N.

Draw a free-body diagram for the mass and write out Newton's 2nd law in the x and y directions.

8. Jan 22, 2008

### VanKwisH

the y-components are not equal though right??

9. Jan 22, 2008

### awvvu

No, because the angles are different.

10. Jan 22, 2008

### VanKwisH

huh............ i said " they are NOT EQUAL " .......
since they are at different angles they are not the same right??
but where would i start at this problem??

11. Jan 22, 2008

### awvvu

Yeah, I'm saying you're right, they aren't equal.

Read what I said earlier, 'Draw a free-body diagram for the mass and write out Newton's 2nd law in the x and y directions.'

12. Jan 22, 2008

### VanKwisH

alright i got the FBD ......... but for newton's 2nd law ........
are u talking about the Fnet = ma in the x and y direction or a different one??

13. Jan 22, 2008

### awvvu

Yes, write out the net forces in the x and y direction. Not sure what you're asking.

14. Jan 22, 2008

### VanKwisH

alright is it
Fnetx = fax + fbx = 0N
Fnety = fay + fby + fg = 0N
cause it's in equilibirum right??

15. Jan 22, 2008

### awvvu

Yep.

16. Jan 22, 2008

### VanKwisH

still doesn't make any sense to me ...... :S i don't have an Fa nor Fb
so i can't use trig ....... what do i do next?