- #1
Feodalherren
- 605
- 6
Homework Statement
Find the acceleration of both blocks
Homework Equations
Dynamics
The Attempt at a Solution
Everything in black is given in the problem. The red/blue is my work.
First I want to relate the acceleration of block A to block B by finding the constraint equations:
Lrope = 2L1 + L2 + 2L3 + constants(lengths around pulleys)
taking the derivative twice to find the acceleration:
0 = 2L1 + L2 + 2L3
I feel like I have too many variable here. I should be able to knock it down to two so that I can relate the acceleration of A to B, correct? How would I do that?
The forces on B, all in Y using the normal xy-coordinate system.
MbAb = 3T - Mb(g)
The forces on A, using a coordinate system along the incline where n1 is "up" and n2 is positive along the slope DOWN:
Sum of the forces in n1 = ma(n1) = Na - mgCos30
Sum of the foces in n2 = ma(n2) = -2T - Fa + mgSin30
Relating the two coordinate systems:
n1 = Cos 30 j - Sin30 i
n2 = -sin30 j - cos30 i
Have I done everything correctly so far?