Multiple Choice
1.2 The Scientific Methods
A scientist wishes to study the motion of about 1,000 molecules of gas in a container by modeling them as tiny billiard balls bouncing randomly off one another. Which of the following is needed to calculate and store data on their detailed motion?
- a group of hypotheses that cannot be practically tested in real life
- a computer that can store and perform calculations on large data sets
- a large amount of experimental results on the molecules and their motion
- a collection of hypotheses that have not yet been tested regarding the molecules
1.3 The Language of Physics: Physical Quantities and Units
Suppose that a bathroom scale reads a person’s mass as 65 kg with a 3 percent uncertainty. What is the uncertainty in their mass in kilograms?
- 2 kg
- 98 kg
- 5 kg
- 0
A high school track coach has just purchased a new stopwatch that has an uncertainty of ±0.05 s . Runners on the team regularly clock 100-m sprints in 12.49 s to 15.01 s . At the school’s last track meet, the first-place sprinter came in at 12.04 s and the second-place sprinter came in at 12.07 s . Will the coach’s new stopwatch be helpful in timing the sprint team? Why or why not?
- No, the uncertainty in the stopwatch is too large to effectively differentiate between the sprint times.
- No, the uncertainty in the stopwatch is too small to effectively differentiate between the sprint times.
- Yes, the uncertainty in the stopwatch is too large to effectively differentiate between the sprint times.
- Yes, the uncertainty in the stopwatch is too small to effectively differentiate between the sprint times.