Home Technical Mathematics Languages Science Social Science Art Literature Arabic Islamic Studies C.R.K History MusicVisual Art Clothing/Textile Home Management Shorthand
 Physics Paper 1, MAy/June. 2009
 Questions: 1 2 3 4 5 6 Main

Weakness/Remedies
Strength

Question 1

(a)  Diagram

(i)You are provided with two metre rules and other necessary apparatus.

(ii)Place one of the rules on a knife edge and determine its centre of gravity C.  Mark this position with a piece of chalk.

(ii)Read and record the mass MR of the metre rule written on the reverse side of it.

(iv)Attach the mass M = 100 g firmly to the rule AB at C using sellotape.

(v)Suspend the metre rule by two parallel thread of length h = 40 cm each at the 10 cm and 90 cm marks.  Ensure that the graduated face of the metre rule is facing upwards.

(vi)Set the rule AB into a small angular oscillation about the vertical axis through its centre of gravity.

(vii)Determine the time t for 20 complete oscillations.  Evaluate the period T and T2.

(viii)Read and record the value of d in metres.

(ix)Keeping d constant throughout the experiment, repeat the procedure for other values of h = 50, 60, 70 and 80 cm.  In each case determine the corresponding values of t, T and T2.  Tabulate your readings.

(x)Plot a graph of T2on the vertical axis and h on the horizontal axis.

(xi)Determine the slope s, of the graph.

Evaluate k = s
Q
where Q =  2
25d2

(xii)State two precautions taken to ensure accurate results

(b)  (i)  Define the term couple as it relates to rotational or oscillatory systems.
(ii)    Give two practical applications of a couple in everyday life.

_____________________________________________________________________________________________________
Observation

This question was popular and fairly attempted by some candidates.  Some of the candidates who attempted it failed to record measured values to the required number of decimal places.  Measured values were reduced to 1 significant figure before plotting thereby making candidates lose marks.  For instance 0.0325 was reduced to 0.03.  This shifted the exact point away on the graph by two boxes.

The part (b) was not also properly answered by most candidates as some confused couple with moments.  Where definition of couple was successfully  stated, candidates could not give practical example/applications in everyday life as demanded by the question.

The demands of part (a) include the following:

1. evaluate five values of T and T2
2. Data should be measured to 1 decimal place and recorded in a composite table (showing h, t, T andT2);  (Trend; t increases as h increases)
3. The graph axes should be indicated and  reasonable scales selected to plot the five points required;
4. In order to determine the slope a large right angled triangle should be drawn on the graph line;
5. Precautions to ensure accurate results:

Ensured that the support of the bifilar pendulum is rigid.
Avoided parallax error in reading the metre rule/stop watch.
Ensured (smooth and regular) oscillations in a  horizontal plane.
Avoided zero error in the reading of stop watch/clock.

(b)(i)    Definition of the term Couple
- Two forces of equal magnitude acting in opposite directions but not along
the same line.

1. Practical applications of a couple in everyday life:

-   Opening/closing of taps
-   Turning a steering wheel of a vehicle
-    Setting a fly wheel in motion about an axis through its centre
-    Motion of a spinning spindle
-    Riding/pedaling of bicycle
-    Turning a spanner