Page 5 - SP015 Past Years PSPM Chapter 6 -14 Ver 2020

PSPM SP015

PSPM 2010/2011 SF017/2 No. 3

16. A 0.2 kg ball, attached to the end of a string, is rotated in a horizontal circle of radius
1.5 m on a frictionless table surface. The string will snap when the tension exceeds
50 N.

(a) What is the maximum speed of the ball? [2 m]

(b) If there were friction on the table, what will happen to the maximum speed of the
ball? Explain your answer. [2 m]

PSPM 2010/2011 SF017/2 No. 11

17.
A O

L = 2 m

B
FIGURE 6.7

A small bob of mass 10 g is attached to the end of a massless string of length 2 m. The
other end of the string is fixed at point O as shown in FIGURE 6.7. Initially, the bob is
held at point A which is at the same level as point O, keeping the string taut and then
released. Determine

(a) the linear velocity of the bob at point B directly beneath point O. [3 m]

(b) the angular velocity of the bob at point B. [2 m]
(c) the tension of the string when the bob is at point B. [4 m]
(d) the linear velocity of the bob at a point midway through arc AB. [3 m]

(e) whether the linear velocity of the bob at point B be lower, higher or similar if the
experiment is performed on the surface of the moon. Explain your answer briefly.
[3 m]

PSPM 2011/2012 SF016/2 No. 4(b)

-1
18. A 3500 kg car enters a curve of radius 10 m on a flat road at 30 m s .

(a) Calculate the net horizontal force required to keep the car moving around the
curve without slipping. [2 m]

(b) State the force that enables the car to successfully negotiate the curve. [1 m]

5