Distance against displacement, speed against velocity, s = vt and changing km/h into m/s.
What you will learn
- Tell a scalar from a vector
- Calculate speed, distance or time with s = vt
- Convert km/h to m/s
Distance or displacement
Walk 300 m to the shop and 300 m back.
You have covered a distance of 600 m, but your displacement is 0 m: you ended where you started.
- Distance is how far you travel. It has a size only, so it is a scalar.
- Displacement is how far you end up from the start, in a straight line, and in which direction. It has a size and a direction, so it is a vector.
Other pairs work the same way: speed (scalar) and velocity (vector), mass (scalar) and weight (vector, it points down).
The rest of this lesson and its 8 practice questions are locked.
In this lesson
- Distance or displacement
- Speed and velocity
- km/h into m/s
- Try it: Your first speed calculation
8 practice questions, marked as you go; about 20 minutes in all.
Key terms
Distance, Displacement, Scalar, Vector, Average
In this unit: Forces and motion
Speed, velocity and acceleration, the graphs that show them, the equations of motion, Newton's laws and stopping distances.