The speed of a bullet train is measured to be 312.0 mpg +/- 3.9 mph. What is the percent uncertainty in this measurement?(1 point) Responses 1.3 % 1.3 % .13 % .13 % 14.4% 14.4% .14 %

1 answer

To calculate the percent uncertainty, you can use the following formula:

\[ \text{Percent Uncertainty} = \left(\frac{\text{Uncertainty}}{\text{Measured Value}}\right) \times 100% \]

In this case, the measured value is 312.0 mph and the uncertainty is 3.9 mph.

Substituting the values into the formula:

\[ \text{Percent Uncertainty} = \left(\frac{3.9}{312.0}\right) \times 100% \]

Calculating that gives:

\[ \text{Percent Uncertainty} = \left(0.0125\right) \times 100% \approx 1.25% \]

Rounding to three significant figures, the percent uncertainty is approximately 1.3%.

Thus, the correct response is 1.3%.