Recent content by tiny-tim

™ ! :smile:

hi dsy5037! welcome to pf! :smile: your method is correct, but you've not thought out the PE difference correctly … not all the 1.6 m of string has fallen 1.6 m, has it? :wink:

(just got up :zzz:) i don't understand this :confused: to integrate dv/dt = f(v), write it dv/f(v) = dt, then integrate both sides :smile:

write out the equation properly, and solve it (using v(0) = 0), and all that should become clear :smile: (and now I'm off to bed :zzz:)

(or Av+B = AoeAt) that gives you v as a function of t, from which you can get the induced emf :smile:

it's something like dv/dt = Av + B, or dv/(Av + B) = dt … can you solve that? :smile:

your RHS is a function of x' :smile:

you are fundamentally misunderstanding what it means for a force to act on a body :redface: there are two forces acting on the mass: i] its weight, mg vertically down ii] the reaction force from the rod, mg vertically up these forces balance, and so the mass stays where it is there are...

so what? the weight of the mass acts only on the mass how can the weight of the mass act on the rail?

hi playoff! :smile: no, a = dv/dt is a function of v, not a constant :wink:

you have mx'' equals a function of x' … write the equation out, and solve it! :smile:

hi sozener1! :smile: hint: the eg top-right-hand corner is also a node, and has one current going in and one current going out sooo … ? :wink:

Hi Fantasist! :smile: Sorry, but this is meaningless :redface: … the gravitational force acts through the mass m, and has nothing to do with the rail. (If you mean the reaction force, it is always perpendicular to the frictionless rail, and so does no work.)

hi subzero0137! :smile: the acceleration will be less than gsinα because the constant gravitational component of force is opposed by the velocity-dependent electromagnetic force :wink:

yes this is correct 21/7 miles minus 20/7 miles = 1/7 miles west 14/7 miles minus 15/7 miles = minus 1/7 miles east = 1/7 miles west either way you get 1/7 miles west :smile: i don't understand what you're not getting about this :confused: