Review for Ch 1 & 2 Quiz: Converting Units, Constant & Avg. Speed/Velocity, Acceleration
Unit Conversions: When using prefixes like micro (µ), milli (m), kilo (k), giga (G), etc., make sure to “translate”
the prefix’s meaning to the other half of the conversion factor. When converting units that are squared you will
have to use the conversion factor twice. (Note: prefixes can go with any unit, like g, m, s.)
Since µ=10-6, we can write 1µs = 10-6s and the conversion factors: __1 µm _ = 1 and _10-6 m_ =1
10-6 m
1 µm
Solve the following on a separate sheet of paper:
1. a. 9.25ms = _______s
b. 24.3 cm = _________μm
c. 6.50 kg cm/min² = __________kg m/s²
2. If a man’s jogging speed is 2.54m/s, how long would it take him to run 125m at that speed?
3. a) A woman running west at a constant velocity decides to speed up. She accelerates uniformly to the west
and runs 25.3m west in 6.12s. If she ends up getting up to a velocity of 5.05m/s west, how fast was she going
originally? b) If she had run the same distance in 5.50s, what would her average velocity have been during her
acceleration?
4. If a car’s motion goes from 2.54m/s north to 4.17m/s north in 2.75s, what is its acceleration?
5. A person tries to calculate their reaction time by having a friend drop a ruler between their fingers and
measuring how far the ruler falls. If in 3 trails the ruler falls 20.25cm, 21.03cm, and 19.56cm, what was the
person’s average reaction time?
6. What is the difference between speed and velocity?
7. Is it possible to have a negative acceleration and a positive velocity?_____ If not, explain why not. If so, give
an example. (Make sure to explain what direction it is that you are choosing as positive.)
Review for Ch 1 & 2 Quiz: Converting Units, Constant & Avg. Speed/Velocity, Acceleration
Unit Conversions: When using prefixes like micro (µ), milli (m), kilo (k), giga (G), etc., make sure to “translate”
the prefix’s meaning to the other half of the conversion factor. When converting units that are squared you will
have to use the conversion factor twice. (Note: prefixes can go with any unit, like g, m, s.)
Since µ=10-6, we can write 1µs = 10-6s and the conversion factors: __1 µm _ = 1 and _10-6 m_ =1
10-6 m
1 µm
Solve the following on a separate sheet of paper:
1. a. 9.25ms = _______s
b. 24.3 cm = _________μm
c. 6.50 kg cm/min² = __________kg m/s²
2. If a man’s jogging speed is 2.54m/s, how long would it take him to run 125m at that speed?
3. a) A woman running west at a constant velocity decides to speed up. She accelerates uniformly to the west
and runs 25.3m west in 6.12s. If she ends up getting up to a velocity of 5.05m/s west, how fast was she going
originally? b) If she had run the same distance in 5.50s, what would her average velocity have been during her
acceleration?
4. If a car’s motion goes from 2.54m/s north to 4.17m/s north in 2.75s, what is its acceleration?
5. A person tries to calculate their reaction time by having a friend drop a ruler between their fingers and
measuring how far the ruler falls. If in 3 trails the ruler falls 20.25cm, 21.03cm, and 19.56cm, what was the
person’s average reaction time?
6. What is the difference between speed and velocity?
7. Is it possible to have a negative acceleration and a positive velocity?_____ If not, explain why not. If so, give
an example. (Make sure to explain what direction it is that you are choosing as positive.)