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

114

Aptitude Test Problems in Physics

The magnitude of the vertical velocity component

for the first impact against the bottom is 20,

and the time of motion from the top to the bottom

of the well is t 2 = 1/2H/g.

ri

Fig. 125

Figure 126 shows the vertical plane develop-

ment of the polyhedron A 1 ,4 2 A 3.. On this

development, the segments of the trajectory of the

ball inside the well are parabolas (complete para-

Fig. 126

bolas are the segments of the trajectory between
successive impacts against the bottom). The ball
can "get out" of the well if the moment of the
maximum ascent along the parabola coincides with
the moment of an impact against the wall (i.e. at
the moment of maximum ascent, the ball is at
point An of the well edge). The time t 1 is connected
to the time t 2 through the following relation:

nti = 2kt2,