- #1

- 1

- 0

**Incredibly hard Physics homework!**

Alright, so here's the problem:

Three known masses are connected together by four pieces of ideal string of known length. Determine the tensions in the strings and the unknown angles, given any value for the length of the strings and the weights.

http://img122.exs.cx/img122/6239/75-physicsproblem.jpg

So far, I've been able to pull this information from the question:

0 degrees < {|A1|, |A2|, |A3|, |A4|} < 90 degrees

The direction that the angles will go will depend on whether the values of the angles are positive or negative.

T1 cos A1 = T2 cos A2 (1)

T2 cos A2 = T3 cos A3 (2)

T3 cos A3 = T4 cos A4 (3)

T1 sin A1 - T2 sin A2 = m1g (4)

T2 sin A2 - T3 sin A3 = m2g (5)

T3 sin A3 - T4 sin A4 = m3g (6)

l1 cos A1 + l2 cos A2 + l3 cos A3 + l4 cos A4 = L (length of top bar) (7)

l1 sin A1 + l2 sin A2 + l3 sin A3 +l4 sin A4 = 0 (8)

Given: l1, l2, l3, l4, L, m1, m2, m3

Find: T1, T2, T3, T4, A1, A2, A3, A4

How does one go about solving these non-linear equations?

I've solved this for 1 mass and halfway done solving this for 2 masses. Solving this for 3 masses is much harder though. Can anyone please help?

Last edited: