Precise measurements of physical quantities are essential in modern science. Which of the following situations best illustrates the need for high-precision measurements of physical quantities such as length, time, or mass?
| 1. | Measuring the speed of an aircraft using radar with nanosecond time resolution. |
| 2. | Measuring the room temperature using a standard laboratory thermometer. |
| 3. | Estimating the weight of vegetables using a mechanical balance. |
| 4. | Observing rainfall using a manual rain gauge. |
