Question

2. A student measured the mass and volume of three different-sized samples of sand. He then calculated the

density of each sample. His results are shown below.
Sand Sample
1
2
3
Mass (8)
10
15
20
Volume (ml)
4.5
5.6
6.7
Density (g/mL)
2.2
2.7
3.0
How do you know just by looking at the "Density" column that the student made errors in his investigation?

Answer 1

9514 1404 393

Answer:

we expect the results to have less spread

Explanation:

The spread between the maximum and minimum is almost 1/3 of the average of those values (0.8 vs 2.6). We expect repeated measurements of the same physical value to be well within 5% of their mean if they are done carefully.

The investigation has errors because the spread is too great.