Page 8 - SP015 Past Years PSPM Chapter 6 -14 Ver 2020

PHYSICS PSPM SEM 1 1999 - 2017

PSPM 2016/2017 SF016/2 No. 4(b)

24.



FIGURE 6.10

FIGURE 6.10 shows a 250 g bob suspended by a light string rotating in a horizontal
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circle of radius 30 cm with a linear speed of 2 m s .

(a) Calculate the angle  which the string makes with the vertical axis. [3 m]

(b) Calculate the tension in the string. [1 m]

(c) If the speed is increased, how would it affect the circular motion of the bob?
Explain your answer. [2 m]

PSPM 2017/2018 SF016/2 No. 4(c)

25.

T a

50°
50°

T b

FIGURE 6.11

FIGURE 6.11 shows a 4.0 kg object is attached to a vertical rod by two strings. The
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object rotates in a horizontal circle of radius 1.30 m at constant speed 6.0 m s .
Calculate the

(a) tension T a in the upper string. [6 m]
(b) tension T b in the lower string. [1 m]

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