Aptitude Test Problems in Physics Science for Everyone by S Krotov ( PDFDrive.com )

length of the thread

17/ 2 ±(L/2) 2

and the free-fall acceleration

L/2

= g

I /1 2 + (L/2) 2

(^196) Aptitude Test Problems in Physics
where L = AD.
Thus, the required period of small oscillations
of the system is
T =2n17 —7=2n 1/1- —

21

.

g

1.99. In order to solve the problem, it is sufficient
to note that the motion of the swing is a rotation

Fig. 190

about an axis passing through the points where

the ropes are fixed, i.e. the system is a "tilted sim-

ple pendulum" (Fig. 190). The component of the

force of gravity mg along the rotational axis does

not influence the oscillations, while the normal

component mg sin a is in fact the restoring force.