Homework Statement
A train of length L moves at speed 4c/5 eastward, and a train of length 3L moves at speed 3c/5 westward. How fast must someone run along the ground if he is to coincide with both the fronts-passing-each-other and backs-passingeach-other events?
Homework Equations
Velocity...
For a single particle in a 2D square lattice in the presence of an Abelian magnetic field Schroedinger's equation transforms into Harper's equation
g(m+1) + g(m-1) = [E - 2 cos(2\pi m \alpha- \nu)]g(m)
where
\psi(x,y)=\psi(ma,na) = e^{i\nu n} g(m) \\ \alpha= \frac{e a^2 B}{h c}
I am familiar...
I was told to use virtual work principle, but I don't see any starting point. Nevertheless I am going to stick with static solution. Thank you for your answer.
Homework Statement
A loop of flexible chain, of total weight W, rests on a smooth, frictionless right circular cone of base radius r and height h. The chain rests in a horizontal circle on the cone, whose axis is vertical. Find the tension in the chain.
Homework Equations
Virtual work, but...