Question

When nonmetric units were used in the United Kingdom, a unit of mass called the pound-mass (lbm) was used, where 1lbm=0.4539kg.

(a) If there is an uncertainty of 0.0001 kg in the pound-mass unit, what is its percent uncertainty?

a) 0.022%
b) 0.044%
c) 0.066%
d) 0.088%

Answer 1

The percent uncertainty of the pound-mass (lbm) unit with an uncertainty of 0.0001 kg is approximately 0.022%.

Step-by-step explanation:

When using nonmetric units such as the pound-mass (lbm) in the United Kingdom, 1 lbm is equivalent to 0.4539 kg. The percent uncertainty of the pound-mass when an uncertainty of 0.0001 kg is presented can be calculated using the formula for percent uncertainty, which is (uncertainty / value) × 100%.

To calculate the percent uncertainty, divide the uncertainty by the value of the pound-mass unit and multiply by 100. In this case, the uncertainty is 0.0001 kg and the value of the pound-mass unit is 0.4539 kg. So, the percent uncertainty is (0.0001/0.4539) * 100 = 0.022%

Therefore, the percent uncertainty is (0.0001 kg / 0.4539 kg) × 100%, which equals approximately 0.022% (option a).