THE TERMINOLOGY
The total length of the path an object travels, ignoring direction
What is distance?
On a motion diagram, evenly spaced dots show the object moving at this kind of speed
What is constant (uniform) speed?
On a distance–time graph, a flat horizontal line means the object is doing this.
What is staying still / stationary / at rest?
A car travels 100 m in 20 s. Find its average speed.
What is 5 m/s?
This device prints dots on a paper tape at regular time intervals to record an object's motion.
What is a ticker timer?
The change in an object's position measured in a straight line from start to finish, including direction.
What is displacement?
When the dots get further apart over time, the object is doing this
What is speeding up / accelerating?
On a distance–time graph, this feature of the line tells you the object's speed.
What is the gradient (slope)?
A runner moves at 8 m/s for 15 s. How far do they travel?
What is 120 m?
A ticker timer vibrating 50 times per second makes one dot every this length of time.
What is 0.02 s (1/50 of a second)?
The vector quantity that describes how fast an object moves and in what direction.
What is velocity?
When the dots get closer together over time, the object is doing this
What is slowing down / decelerating?
A straight diagonal line on a distance–time graph shows this type of speed.
What is constant (steady) speed?
A cyclist covers 600 m at a steady 10 m/s. How long does it take?
What is 60 s?
On ticker tape, dots that are far apart and getting even further apart tell you the object is doing this.
What is accelerating (speeding up)?
The rate at which an object's velocity changes over time
These arrows are added to motion diagrams to show the size and direction of an object's velocity
What are velocity vectors?
On a velocity–time graph, the gradient of the line represents this quantity.
What is acceleration?
A car speeds up from 0 to 20 m/s in 4 s. Find its acceleration.
What is 5 m/s²?
This electronic device uses ultrasound to measure distance and sends motion data straight to a computer.
What is a motion sensor (data logger)?
Distance and speed belong to this group of "magnitude-only" quantities.
What are scalar (quantities)?
A diagram shows dots close together, then gradually further and further apart. Describe the motion.
What is starting slow (slow constant speed) then accelerating (speeding up)?
On a velocity–time graph, the area under the line represents this quantity.
What is the distance travelled?
A skateboarder slows from 12 m/s to 2 m/s in 5 s. Find the acceleration.
What is −2 m/s² (decelerating at 2 m/s²)?
Name one advantage a motion sensor has over a ticker timer.
What is more accurate / gives instant real-time graphs / no manual tape-measuring / collects more data points?