OK thank you very much. I got it. I wrote the vectors of r and v in cylindrical coordinates and indeed the cross product generates zero momentum along the vertical axis. You are right no external toques anyways act on the system so angular momentum has to be conserved vertically but not...
Thanks. Yes I completely understand but the velocity is not vertically down it is at an angle as in image and the cross product spans an inverted cone with a horizontal top circle as the cone in question is spinning ie it has a component of angular momentum along that vertical axis that adds up...
Why not? That component should be contributing. See image please.
I am sorry I don't understand r×v should be out of the page and hence contributes to L no?ℂ
Homework Statement
A cone of height h and base radius R is free to rotate around a fixed vertical axis. It has a thin groove cut in its surface. The cone is set rotating freely with angular speed ω0, and a small block of massm is released in the top of the frictionless groove and allowed to...
Solution only uses change in I to arrive at w. I did part a no problem there but for frequency I am not convinced. Why not:
Li=Lf then wi*Ii=wf*If. only unknown is wf but then you get w0/3 not w0/√3
Homework Statement
A solid disk of mass M and radius R is on a vertical shaft. The shaft is attached to a coil spring that exerts a linear restoring torque of magnitude Cθ, where θ is the angle measured from the static equilibrium position and C is a constant. Neglect the mass of the shaft and...
I got the right answer thank you so much for your help.
For other questions I will continue to snap images of my work I will make sure my handwriting next time is clear and I will use a pen I am sorry I will not type it typing takes lots of time especially the kind of questions I attempt are not...
Sorry it just takes lots of time to type and I work out lots of problems so trying to use time efficiently!Next time I will use ink and make it more neat apologies.
as for v-Δv due to the added mass shouldn't the velocity decrease according to Conservation of Momentum. Wrong? I tried changing...
Homework Statement
Freight car and hopper*
An empty freight car of mass M starts from rest under an applied force F. At the same time, sand begins to run into the car at steady rate b from a hopper at rest along the track.
Find the speed when a mass of sand m has been transferred.Homework...