MOTION BASICS
What kind of quantity has magnitude only?
A scalar
What is the formula for speed?
speed = distance ÷ time
Question: A car moves at 12 m/s for 5 s. How far does it travel?
Answer: 60 m
Question: On a position-time graph, what does the slope represent?
Answer: Velocity
Question: What is the SI unit for distance?
Answer: Meter (m)
What kind of quantity has both magnitude and direction?
Vector
What is the formula for velocity?
velocity = displacement ÷ time
Question: An object travels 240 m at 30 m/s. How long does the trip take?
Answer: 8 s
Question: On a velocity-time graph, what does the slope represent?
Answer: Acceleration
Question: What is the SI unit for time?
Answer: Second (s)
A student walks 80 m east, then 30 m west. What is the student's displacement?
50 m east
A car travels 150 m in 10 s. What is its speed?
Answer: 15 m/s
Question: A ball travels 56 cm in 7 ms. What is its speed in m/s?
Answer: 80 m/s
Question: On a velocity-time graph, what does the area under the graph represent?
Answer: Displacement
Question: How can you use units to check whether you have solved a problem correctly?
Answer: Plug in the units and simplify/cancel them to see whether the final unit is correct.
A runner completes a 200 m loop and finishes where they started. What are the runner's distance and displacement?
Distance = 200 m; displacement = 0 m
A cyclist travels 120 m west in 8 s. What is the average velocity?
Answer: 15 m/s west, or −15 m/s
A cyclist travels at 25 m/s. What is this speed in km/h?
Answer: 90 km/h
Question: What does a flat line on a position-time graph represent?
Answer: The object is at rest
Question: A length is measured as 4.20 m and a time as 2.5 s. To how many significant figures should the calculated speed be reported?
Answer: 2 significant figures
Can an object's distance traveled ever be less than the magnitude of its displacement?
No. Distance is always greater than or equal to the magnitude of displacement
Why can velocity be zero while speed is not zero?
Answer:
If an object returns to its starting point, its displacement is zero even though it traveled a nonzero distance.
A runner completes 5,000 m at a speed of 4.3 m/s. About how long does the run take?
Answer: About 1,163 s, or 19.4 min
Question: In a motion diagram, the dots get farther apart from left to right. What does this indicate?
Answer: The object is speeding up, or accelerating
Question: Student A measures a track three times as 100.2 m, 100.1 m, and 100.3 m. What quality do these measurements demonstrate, and why?
Answer: High precision because the repeated measurements are tightly clustered.