Distance/Displacement
A runner jogs 10 m west, then 10 m east. What is their distance and displacement?
Distance: 20 m
Displacement: 0m
A plane is flying at 600 km/h. To a passenger inside the plane, how does another passenger appear?
Stationary, because they share the same velocity inside the plane.
A car drives 120 km in 2 hours. What is its speed?
60 km/h
When is an object considered to be accelerating?
- When an object speeds up/slows down
- When an object changes direction
On a distance-time graph, a flat horizontal line means:
object is stationary
A student walks 12 m north, then 5 m east. What is their distance and displacement?
Displacement: 13m NE
Distance: 17 m
A student is sitting in a moving bus and sees a tree pass by the window. To the student, does the tree appear to move? Why?
Yes, because the student is using themselves as the reference point. Relative to them, the tree moves backward.
A cyclist rides at 10 m/s for 200 seconds. How far does she travel?
2000 m
A rocket car travels around Earth at constant speed. Accelerating or not?
Accelerating (direction is changing)
On a velocity-time graph, a straight horizontal line above a value of 0 means
constant velocity
A dog runs around a full circle track of radius 4 m. What is its distance and displacement?
Distance: 25.1 m (8pi)
Displacement: 0 m
What makes a good reference point?
- Stationary
- Must be in the same area as the object
Car A drives 300 km in 5 hours. Car B drives 250 km in 4 hours. Which car is faster, and by how much?
Car A: 60 km/h, Car B: 62.5 km/h → Car B is faster by 2.5 km/h.
A student runs from 0 to 11 m/s in 9 s. What is their acceleration?
Acceleration is about 1.2 m/s²
What is the acceleration in Section B?
0 m/s^2
You walk 6 m north, then 8 m south. What is your distance/displacement?
Distance: 14 m
Displacement: 2 m S
You are standing on a train platform as a train passes by. To you, the train looks like it’s moving. To someone inside the train, how do you appear?
Moving backward at the same speed the train moves forward.
A runner completes one full lap around a circular track of 400 m in 100 seconds. What are their speed and velocity?
Speed = 4 m/s; Velocity = 0 m/s (displacement is 0).
A rocket goes from 50 m/s to 1000 m/s at 550 m/s². What is the time the rocket took to reach its final velocity?
Time is about 1.7 seconds
What is the acceleration in Section D?
-1.25 m/s^2
A horse runs halfway around a circle of radius 10 m. What is its distance and displacement?
Distance: 31.4 m (10pi)
Displacement: 20 m
Why is motion considered relative?
Motion is relative because it is always measured by comparing an object to a background or a point of view.
A swimmer swims 100 m downstream in 50 s, then 100 m upstream in 100 s. What is their average speed and average velocity?
Average speed = 1.33 m/s; Average velocity = 0 m/s (same start and end point).
An object has acceleration of 0 m/s².
What are two possible motions can this object have?
The object is either at rest or moving at constant velocity.
What is the distance traveled in section A?
75 m