Page 29 - SP015 Past Years PSPM Chapter 6 -14 Ver 2020

PSPM SP015

PSPM 2014/2015 SF016/2 No. 5(c)

52.

FIGURE
8.23
FIGURE 8.23 shows a ball attached to one end of a string which is swung in a
-1
horizontal circle of radius 60 cm with an initial speed of 3 m s . The other end of the
string passes through a tube. If the string is slowly pulled downwards until the speed of
-1
the ball becomes 5 m s , what is the radius of the circular path of the ball?
[3 m]

PSPM 2016/2017 SF016/2 No. 5(d)

53.
ball

5 m s -1
pivot

1 m

FIGURE 8.24

FIGURE 8.24 shows a top view of a 1 m rod pivoted freely at its center and placed
-1
horizontally. A 20 g ball with velocity 5 m s collides and sticks at one end of the rod
2
causing them to rotate. The moment of inertia of the ball-rod system is 0.02 kg m .
Calculate the angular velocity of the rod. [4 m]

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