She places a load P on the metre rule so that the edge that is furthest from the pivot is exactly
at the 10.0 cm mark on the rule.
She measures the distance a between this edge of the load P and the pivot, as shown in
Fig. 1.1.
She places a load Q on the metre rule and adjusts the position of load Q so that the metre
rule is as near as possible to being balanced.
She measures the distance b between the centre of load Q and the pivot, as shown in
Fig. 1.1.
She repeats the procedure, with the edge of the load P that is furthest from the pivot at the
15.0 cm, 20.0 cm, 25.0 cm and 30.0 cm marks. All the readings are shown in Table 1.1.
Table 1.1
a/cm
|
b/cm
|
38.0
|
44.5
|
33.0
|
38.5
|
28.0
|
33.6
|
23.0
|
27.2
|
18.0
|
22.0
|
Plotagraph of a/cm(y-axis) against b/cm(x-axis).Start both axes at theorigin (0,0).
graph:
axes correctly labelled and right way round
suitable scales starting from (0,0)
all plots correct to less than ½ small square
good line judgement, thin, continuous line