Table 4.

Mass of the objects (g)	Experiment 1.1	Experiment 1.2
Known
Known

 

Table 4, shows what kind of masses were used in Experiment 1.1 and Experiment 1.2.

After getting Free Body Diagrams and Tables with data, can be started calculating part.

Formulas.

Will be used standard formula (1.1) and then simplified for our Experiments:

(Formula 2.1)

Calculating for Experiment 1.1

For calculation in Experiment 1.1, the raw data, which in table, should be substituted into formula (2.1).

Then, need to simplify this formula:

(Formula 3.1)

Calculating for Experiment 1.2

For calculation in Experiment 1.2, the raw data, which in table, should be substituted into formula (2.1).

(Formula 3.1.1)

Then, need to simplify this formula:

(Formula 3.2)

After getting simplified formulas (3.1) and (3.2), the COM and mass of the bar could be found.

To find the mass of the bar, need to subtract from formula (3.2) formula (3.1):

Hence,

To find the centre of mass of the bar, need to substitute the mass into the formula (3.2.2):

 

Hence, mass and COM of bar were found. Experiment 1.1 and Experiment 1.2 is done.

Part D1 (Calculating Errors)

The original mass of the irregular shaped bar is 232.4 and COM is 46.5cm.

Compare to experimental result, can be clearly seen that was made some errors during the Experiments. Hence, errors should be calculated in the percentage.

Error of mass:

Error of COM:

 

Part A2 (Experiment 2.1 with the 2^nd irregular shaped bar)

First of all, will be explained how all system were set up. In the beginning iron stand was connected to the triple beam balance. Then, using light string, bar was randomly connected to the iron beam. Then two known masses hanged to the bar and fixed in position, where whole system was balanced.

The Figure 8, which is above, will give the visual information about how equipment was set up.

Figure 8.

 

Therefore, must to have free body diagram, as was did in the experiments before.