Is there anyone who can solve this problem??

i'd like to know about the moment of the point A

[Bob Thompson]

Is the system statically stable? Also, how much does the crane weigh? I don't know that language.

[dongkeun lee]

yes its stable and there's no information about the crane weigh. and i'll translate for you

<When 120 kN of tension is applied to the hoisting cable of the crane, calculate the moment for point A.>

(1) When the crane angle is 30 degrees

(2) When the crane angle is 60 degrees

[dongkeun lee]

and I know about thoes mathematical formula. but i didn't know how to make a work into matlab as computer language.

1.((15m*cos30+2m-4m)*(120kN*sin60)+(4m+sin30)*(120kN*cos60))

[Bob Thompson]

What do you mean by, 'make a work into matlab as a computer language?' Are you just trying to perform the two calculations in Matlab? Are you trying to set it up as a force and moment solver that you can enter values dynamically?

[dongkeun lee]

oh man sorry just im trying to perform the two calculations in Matlab. can you help me?

[Bruno Luong]

(4m+sin30)

Just looking at the unit this formula doesn't make any sense in the physical world. One never at a length to a sinus.

[Bob Thompson]

The equation you have written out is mostly what you need. Remove the units (matlab just wants numbers), and use cosd() and sind() to evaluate sine and cosine for degree values. I would also double check (4m+sin30). I could be seeing things wrong, but something seems off with it.

If you need a more specific script line than that let me know.

[dongkeun lee]

you're so sweet thanks a lot. but actually, i made up that (15*cosd(30)+2-4)*(120*sind(60))+(4+sind(30))*(120*cosd(60))

but i think i need a whloe specific script line for that. i don't know how to make a script line at all

[Bob Thompson]

It should look something like this:

M_A = (15*cosd(30)+2-4)*(120*sind(60))+(4+sind(30))*(120*cosd(60));

You really had it written out already, just needed the variable equals to 'script' it. You could have also entered everything to the right of the equal size as a 'command' in the matlab command window and the variable 'ans' would be the result you're looking for.

Note that I just wrote the equation you had already, so again, make sure you double check it.

[dongkeun lee]

And how do I separate it from the m unit and the kN?

[Bob Thompson]

It is separated from the units by just using the numbers, not entering any kind of unit symbol. I would suggest keeping the equation written down on paper somewhere though, so that you don't accidently forget what the units should be.

[dongkeun lee]

i appreciate it!! great thanks a lot:) i will do that!:)