Alternative A

 

Question 1A

 

 

 

In an experiment, a fixed mass of 50 g is attached securely at a distance AP = x = 2 cm from one end of a metre rule. Varying mass, m, ranging between 40 g  and 120 g are attached in turns at the centre of gravity G of a metre rule. The loaded metre rule is balanced on a knife edge positioned at Q between A and G as shown in the diagram above.
The length GQ = d is measured and recorded in each case.
The metre rule is slightly displaced sideways and released so that it performs simple oscillations.

 

Fig. 1(a) and Fig. 1(b) on page 3, illustrate the masses mi and the corresponding length di respectively, where i = 1,2,3,4 and 5.
(i)         read and record mi.
(ii)        Measure and record the corresponding di.
(iii)       In each case, evaluate d-1.
(iv)       Tabulate the readings.
(v)       Plot a graph of m on the vertical axis and d-1 on the horizontal axis, starting both                   axes from the origin (0, 0).
(vi)       Determine the slope, s, of the graph.
(vii)      Determine the intercept, c, on the vertical axis.
(viii)      Using the graph, determine d when m = 90 g
(ix)        Calculate R, given that

(x)       State two precautions that are necessary to ensure accurate results when performing the
experiment                        

 

 

Question 1B

 

(i)         State the principle of moments.         

(ii)

 

The diagram above shows a uniform rod pivoted 5 cm from its centre C. A body of mass 50 g is hung 15 cm from C so that the rod balances horizontally. Determine the weight of the rod. [g = 10 ms-2].