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

[VanKwisH]

Homework Statement

http://img251.imageshack.us/img251/3378/14906417xg0.th.png
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?

Homework Equations

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 ??

 

[lukejian]

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

 

[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?

 

[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

 

[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??

 

[VanKwisH]

bump...

 

[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.

 

[VanKwisH]

the y-components are not equal though right??

 

[awvvu]

No, because the angles are different.

 

[VanKwisH]

No, because the angles are different.

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??

 

[awvvu]

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??

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.'

 

[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??

 

[awvvu]

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??

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

 

[VanKwisH]

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

 

[awvvu]

Yep.

 

[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?