Final answer:
The mass of a US nickel is 5.00 g. Slight variations in mass are due to manufacturing tolerances, but for physics calculations, a standard value is typically used unless precise measurements are specified. Measurement uncertainty depends on the precision of the measuring device and is reflected in the significant figures of the reported mass.
Step-by-step explanation:
The mass of a US nickel is 5.00 g. This information can be used for various calculations in physics, such as determining the number of electrons needed to support the weight of the nickel. A nickel's mass can vary slightly due to manufacturing tolerances. However, in physics problems, it's common to use standard values for simplicity unless more precise measurements are provided.
When discussing measurement uncertainty, it's important to consider the precision of the measuring device. For example, if a quarter is weighed on a standard balance, the reading might be 6.72 g, which could vary by ± 0.01 gram depending on the sensitivity of the scale. The mass is expressed with significant figures, and the least significant figure represents the uncertainty in the measurement.