Physics 5054/32 — May/June 2016

Fig. 1.1 shows a $30\text{ cm}$ ruler of total length $L$.

At one end of the ruler there is a 'dead space' of length $d_1$ before the $0.0\text{ cm}$ mark and at the other end there is a 'dead space' of length $d_2$ after the $30.0\text{ cm}$ mark.

(i) Place the ruler provided on Fig. 1.2.

Align the $0.0\text{ cm}$ mark and edge C of the ruler with the lines in the diagram. Draw a line on Fig. 1.2 to mark the position of end A of the ruler. Using Fig. 1.2, measure $d_1$.

$d_1$ = ______

(ii) Using Fig. 1.3, repeat (a)(i) with end B and measure $d_2$.

$d_2$ = ______

(iii) Calculate the total length $L$ of the ruler.

$L$ = ______

(i) Place the ruler on the pivot. Move the position of the ruler until it balances horizontally. Record the scale reading $S_1$ shown on the ruler at the position of the pivot.

$S_1$ = ______

(ii) Place the $10\text{ g}$ mass so that its outer edge is at the $30.0\text{ cm}$ mark on the ruler. Record the scale reading $S_2$ shown on the ruler at the position of the centre of the $10\text{ g}$ mass.

$S_2$ = ______

(iii) With the $10\text{ g}$ mass position in (b)(ii), place the ruler on the pivot and move the position of the ruler until it balances horizontally. The arrangement is shown in Fig. 1.4.

Record the scale reading $S_3$ shown on the ruler at the pivot.

$S_3$ = ______

(iv) Determine the distances $x$ and $y$ shown on Fig. 1.4.

$x$ = ______
$y$ = ______

Calculate the mass $M$ of the ruler using

$$M = \frac{10y}{x}$$

$M$ = ______ $\text{g}$