Bukhovtsev-et-al-Problems-in-Elementary-Physics

OSCILLATIONS AND WAVES 367
If F=O, i. e., with free falling of the cup, T= eo
tions. When F=Mg, we have T=2n { ~ .
and there are no oscilla..
628. The oscillations of the block will periodically displace the cup in a
horizontal plane. Hence, the oscillation period of the block will diminish,
since an additional variable acceleration directed horizontally will appear in
the coordinate system related to the cup (see Problem 624).
629. Let us compare the motion of the centre of the hoop with that of the
end of a mathematical pendulum with a length R- r, Both points describe
the arc of a circle with a radius R - r. Let us assume that the hoop and the
pendulum are at rest at the angle