PROBLEM:

(a) If your speedometer has an uncertainty of 2.0 km/h at a speed of 90 km/h, what is the percent uncertainty?

(b) If it has the same percent uncertainty when it reads 60 km/ h, what is the range of speeds you could be going?

SOLUTION:

Part a

The percent uncertainty is computed as

Part b

The tolerance of the velocity is

Therefore, the range of the velocity is 60±1km/h, or that is 59 to 61 km/h. $\ \qquad \ \color{DarkOrange} \left( \text{Answer} \right)$

PROBLEM:

State how many significant figures are proper in the results of the following calculations:

SOLUTION:

Part A

The answer is limited by 98.2 and 1.01. They are both 3 significant figures. So the result should be 3 significant figures.

Part B

The answer is limited by 18.7. The answer should be 3 significant figures. So the result should be 3 significant figures.

Part C

The answer is limited by 1.60 which is 3 significant figures. So the result should be 3 significant figures.

PROBLEM:

A can contains 375 mL of soda. How much is left after 308 mL is removed?

SOLUTION:

What is left is calculated as

Therefore, 67 mL of soda is left.