Question

An unknown metal rod has an initial length of 39.82 ± 0.02 cm at 21.5 ± 0.2 ^oC. The rod is heated to a temperature of 97.8 ± 0.2 ^oC and the change in length recorded at various temperatures, as shown in the given table.

1. Generate an accurate graph of the change in length as a function of the measured temperature.
2. From the slope, determine the coefficient of linear expansion for the rod.
3. From the intercept, determine the coefficient of linear expansion for the rod.
4. Identify the material of the rod and compare your average results with the “accepted” value.

Table:

T (± 0.2oC)	DL (± 0.002 mm)
21.5	0.000
30.0	0.038
40.0	0.089
50.0	0.133
60.0	0.169
70.0	0.230
80.0	0.274
90.0	0.323
97.8	0.341

Answer 1