# Worksheet: Combining Uncertainties

In this worksheet, we will practice finding the uncertainties in the values of quantities that can be calculated from two or more measured values.

**Q1: **

A wire carries a current of for a time of . What is the percent uncertainty of the charge that passes through the wire in that time?

- A5%
- B0.0625%
- C60%
- D6.25%
- E0.6%

**Q2: **

Three objects have masses of , , and . What is the uncertainty in the total mass of the three objects?

**Q3: **

Cupronickel is an alloy made of copper and nickel. If of cupronickel contains of copper, what is the uncertainty in the amount of nickel it contains?

**Q4: **

An iron block has a mass of . The acceleration due to gravity is . What is the uncertainty in the weight of the block?

**Q5: **

An object has a mass of and is moving at a speed of . What is the uncertainty in the kinetic energy of the object? Start by calculating the uncertainty in , and then calculate the uncertainty in .

**Q6: **

A force of is applied to an object with a mass of . What is the uncertainty in the acceleration of the object?

- A2 m/s
^{2} - B0.4 m/s
^{2} - C40 m/s
^{2} - D0.2 m/s
^{2} - E0.02 m/s
^{2}

**Q7: **

Two resistors that are in series in a circuit have a combined resistance of . One of the resistors, with a resistance of , is removed. What is the uncertainty in the resistance of the remaining resistor?

**Q8: **

A resistor in a circuit has a resistance of . The current through the resistor is . Work out the potential difference across the resistor as well as the percent uncertainty in this value.

- A
- B
- C
- D
- E

**Q9: **

In an experiment, a quantity is found to have a value of . What is the uncertainty in ?

**Q10: **

A scientist must mix the correct volumes of two liquids, liquid A and liquid B, as part of an experiment. He must mix 500 mL of liquid A with 200 mL of liquid B. He uses a measuring cylinder to measure the volume of each liquid first. The measuring cylinder has a resolution of 5 mL. He then mixes the two liquids. What is the uncertainty in the volume of the mixture?

**Q11: **

In an experiment, a quantity is found to have a value of . What is the percent uncertainty in ?

- A0.09%
- B0.6%
- C4%
- D2%
- E9%

**Q12: **

Two resistors have resistances of and . If the two resistors were placed in series, what would the uncertainty of the two resistors together be?

**Q13: **

An object moves along a straight line at a speed of for . Work out the distance that the object moves as well as the uncertainty in this value.

- A
- B
- C
- D
- E

**Q14: **

A sound wave travels through a medium with a speed of . The wavelength of the sound wave is . What is the percent uncertainty in the frequency of the sound wave?

- A
- B
- C
- D
- E