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

46 PROBLEMS
Fig. 73 Fig. 74
189. At, what distance from the bottom of the rod will the
sphere (see Problem 188) fall if the coefficient of friction
k:» ~5.
190. A wire is bent along an arc with a radius R (Fig. 75).
A bead is placed on the wire that can move along it without
friction. At the initial moment the bead was at point O. What
horizontal velocity should be imparted to the bead for it to
get onto the wire again at point B after fiying a certain distance
(AB) through the air?
191. A small body slides down an inclined surface passing
into a loop from the minimum height ensuring that the body
does not leave the surface of the loop (Fig. 76). What symmetrical
segment with an angle ex < 90° can be cut out of the loop
for the body to reach point B after travelling a certain distance
in the air?
A I 8
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A
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o
Fig. 75 Fig. 76