A student measures the mass of an object five times. The actual mass is 50.0 g. The results are shown in Table 1.1. Trial Mass / g 1 52.1 2 52.3 3 52.0 4 52...
Question 1 Report
A student measures the mass of an object five times. The actual mass is 50.0 g. The results are shown in Table 1.1.
| Trial | Mass / g |
|---|---|
| 1 | 52.1 |
| 2 | 52.3 |
| 3 | 52.0 |
| 4 | 52.2 |
| 5 | 52.4 |
What can be said about these measurements?
Answer Details
Precision describes how close repeated measurements are to each other. Accuracy describes how close measurements are to the true value.
All five readings (52.0 to 52.4 g) are tightly clustered within a range of only 0.4 g, so they are precise. However, every reading is about 2 g above the true mass of 50.0 g, so they are not accurate. This pattern suggests a systematic error, such as a zero error on the balance (the scale reading is consistently too high), rather than random fluctuations.
If the readings were scattered widely around 50.0 g, they would be accurate on average but not precise. If they were both clustered tightly and centred on 50.0 g, they would be both precise and accurate.
Download The App On Google Playstore
Everything you need to excel in your exams
