- #1
LCSphysicist
- 646
- 161
- Homework Statement
- All below
- Relevant Equations
- All below
Basically, there is a gravitational field g and a friction force acting on the cylinder, which does not slip in the plane.
The question is, the acceleration of m'.
I solve this question basically by this:
" m*g*dh*sina + m'*g*dh = m*v1*dv1 + m'*v2*dv2 + I*w1*dw1 " {1}
w*r = v1' + v2'
So
The problem is, in {1} i suppose Δ U = - Δ T, until here okay, but i needed to say that:
Δ U = -(m*g*dh*sina + m'*g*dh)
I am trying to see why this is right.
Why not -(m*g*dh*sina) + (m'*g*dh) or +(m*g*dh*sina) - (m'*g*dh)
?
Maybe doing by the other ways, i would eliminate by absurds, or the first way already encompasses the case where one go up and another go down?