Graphs
Displacement
What is the difference between displacement and distance?
Distance = path travelled length
Displacement = distance between start and end points
What kinematic equation relates velocity, acceleration, and time?
V = V0 + at
What is the acceleration due to gravity value?
-9.8 m/s2
What is the unit for distance?
meters (m)
Sketch a position vs. time graph for an object moving at a constant nonzero velocity on the whiteboard.
Graph should show a constant slope that is not flat.
What is average velocity?
The constant velocity it would take to travel the same distance in the same amount of time for any motion. (Or, average between highest and lowest velocities).
A car starts from rest and accelerates at 2 m/s2 for 5 seconds. What is its final velocity?
10 m/s
If you walk north 100m in 50 seconds, what is your average speed?
2.0 m/s
A car moves at a constant velocity of 12 m/s for 30 seconds. What is the displacement?
360 m
Why can't a line be directly straight upwards on a VT graph?
That would mean an infinite acceleration, or, travelling an infinite distance in 0 seconds.
This is the definition of acceleration and its units.
Change in velocity over time -- m/s2
A rock is dropped from rest and falls for 3 seconds. How far does it fall? (Without air resistance)
44.1 m downwards.
A runner completes one lap around a 400 m track in 80 seconds. What is their average speed, and what is their average velocity?
0 m/s
A car moving at a speed of 8.0 m/s enters a highway and accelerates at a rate of 3.0 m/s^2. How fast will the car be moving after it has accelerated for 56 m?
20 m/s? (use vf^2 = vi^2 + 2ad)
It is accelerating.
This quantity is the slope of a position vs. time graph.
Velocity
A car traveling at 25 m/s brakes with an acceleration of –5 m/s². How long does it take to stop?
5.0 seconds
You drive at 20 m/s for 60 s, then stop for 30 s at a red light. What is your average speed during the whole 90 s?
13.3 m/s
A sprinter accelerates from rest to 8 m/s in 2 seconds. What is her acceleration?
4.0 m/s2
A VT graph shows a constant negative slope starting above the x-axis. Describe this motion.
Moving forward slowing down, then when it crosses the x-axis, begins accelerating in the negative (backward) direction.
A downward slope of a VT graph relates to what kind of motion?
Negative acceleration
A train accelerates from 10 m/s to 30 m/s over a distance of 200 m. Find its acceleration.
2.0 m/s2
A car travels 300 m east, then 400 m north. What is the total distance traveled, and what is the displacement?
Distance = 700 m, displacement = 500 m NE
A motorcycle accelerates from 0 to 20 m/s in 100 m. Find the acceleration using kinematic equations.
2.0 m/s2