Recent content by PhoenixWright

Thank you for your answer. Actually, the problem doesn't explain the physical situation we are solving. It only asks us to solve a certain Langevin equation with the initial condition ##X(0)=1##, and then to calculate ## <X(t)|x_0>, <X^2(t)|x_0>-(<X(t)|x_o>)^2, <X(t)X(0)>##. So, I guess we can...

Homework Statement I have simulated Langevin equation (numerically in Matlab) for some specific conditions, so I have obtained the solution ##X(t)##. But now, with the solution I have obtained, I have to calculate ## <X(t)|x_0>, <X^2(t)|x_0>-(<X(t)|x_o>)^2 ## and the conditional correlation...

Thank you!

Homework Statement Consider a system of three aligned spins with S=1/2. There are couplings between first neighbors. Each spin has a magnetic moment ## \vec{\mu} = s \mu \vec{S}##. The system is in a field ## H= H\vec{u_z}## at thermal equilibrium. The hamiltonian is: ##H=J[S(1)S(2)+S(2)S(3)]...

Problem solved. The exercise was wrong, there were 2 pulleys, not only 1.

Thanks, but, anyway, I can't get the solution if I suppose a1 = a2...

This is a pic of the situation:

The pulley is massless. The plane has no motion. I use this: \begin{equation} m_{1}\vec{g} + \vec{N} + \vec{T_{1}} = m_{1}\vec{a_{1}} \ \\ m_{2}\vec{g} + \vec{T_{2}} = m_{2}\vec{a_{2}} \end{equation} Therefore: \begin{equation} T_{1} = m_{1}a_{1} \ \\ T_{2} - m_{2}g = m_{2}a_{2} \ \\ T_{1} =...

m1 is in a plane (it's not inclinated) and m2 is is hanging from a pulley. They are connected by a thread. In m1 we only consider Tension force (because N = mg), and in m2 we consider Tension force and m_{2}g Thanks

Homework Statement You have a a mass, m1, in a plane. This mass is connected to a pulley by a thread, to a mass m2. Prove that: \begin{equation} m_{1} = \dfrac{m_{2}(2g - a)}{4a} \end{equation} Homework Equations The Attempt at a Solution I don't know why, but I can get this...

Thank you! Now I understand it.

Thank you! Then, I think I should add a condition more (one equation), but I have no idea what it is. If I add y = h_0 + v_0sin \alpha t -1/2 gt^2 , I would have h unknown; and I think I don't have more equations...

I have a problem that means: The jet of water from a fire hose comes with a vo speed. If the hose nozzle is located at a distance d from the base of a building, demostrate that the nozzle should be tilted at an angle such that tan \alpha = \frac{v_0^2}{gd} so that the jet strikes the...

Thank you! Eventually I realized I could differentiate again. I believed that in this case I need to apply Coriolis and centrifugal acceleration, but I was reading and saw that could also solve in this way a moment ago.

up :frown: