Question 1
The diagram above illustrates a metre rule whose centre of gravity G is suspended from a rigid pointer PThe distance X betweenGand P is measured and recorded.
The metre rule is slightly displaced sideways and released so that it performs simple oscillations.
The time, t for 20 complete oscillations and the period T of the oscillations are determined and recorded.
The procedure is repeated for four other values of x.
Fig. 1(a) and Fig. 1(b) on page 3, illustrate the distances xi and the corresponding times ti respectively, where i = 1,2,3,4 and 5.
(i) Measure and record xi
(ii) Read and record ti.
(iii) In each case, evaluate x2, T and T2x.
(iv) Plot a graph of x2n the vertical axis and T2x on the horizontal axis, starting both axes from the origin (0, 0).
(v) Determine the slope, s, of the graph.
(vi) Evaluate k = 4π2s.
(vii) State two precautions you would take if you were to perform this experiment in the laboratory.
(b) (i) Explain the term frequency of oscillation of a system.
(ii) A metal wire of mass 2 g and length 50 cm is place under a tension of 100 N. Calculate its fundamental frequency.
The expected response:
o Five values of x correctly measured and recorded to at least 1 d.p. and
o within tolerance of ± 0.1 cm
o (Deduct 1 mark for each wrong or missing value)
o Five values of tcorrectlyread and recorded to at least 1 d.p in seconds
o (Deduct 1 mark for each wrong or missing value)
o Five values of x2correctly evaluated to at least 2 d.p.
o (Deduct ½ mark for each wrong or missing value)
o Five values of T2x correctly evaluated to at least 2 d.p.
o (Deduct ½ mark for each wrong or missing value)
o Five values of T2x correctly evaluated to at least 2 d.p
o (Deduct ½ mark for each wrong or missing value)
o Composite table showing at least x,t,x2,Tand T2x.
o Plot a graph of reasonable scales
Draw line of best fit
Determine the slope
Evaluate k = 4π2s
State any two of the following precautions
e.g
- Avoided/avoid parallax error in reading metre rule/stop clock/stop watch
- Repeated readings stated
- Noted/corrected zero error on metre rule/stop clock/stop watch
- Ensured/ensure pin is firmly clamped
- Avoided/avoid draught
b(i) The number of to and fro motion made by the system in 1 sec
Its unit is Hertz or cycler per second
OR
The number of oscillations completed by the system in 1
second
Its unit is Hertz
(ii)
