Kinematic quantities
Objective. Distinguish scalar and vector motion quantities.
- 1. Learn
- 2. Worked example
- 3. Practice
- 4. Feedback
- 5. Continue
Learn: the key idea
Kinematic quantities describe motion and split into scalars, which have magnitude only, and vectors, which have both magnitude and direction. Distance and speed are scalars, while displacement, velocity and acceleration are vectors, meaning direction matters and negative values indicate a reversed direction. For example, a car travelling 5m east then 5m west has covered a distance of 10m but has zero displacement, since it returned to its start point. Always state direction explicitly or use a sign convention when working with vector quantities.
Worked example
A particle moves 8m to the right then 3m to the left. Find the total distance travelled, a kinematic quantity distinct from displacement.
- 1Distance is the total path length, ignoring direction
- 2Add the magnitudes of each separate movement
- 3Distance=8+3
- 4Distance=11m
Answer: 11m
Concept mastery
Based on your past attempts at this lesson — the question types to practise again come first.
Complete a practice set to see your concept breakdown here.
Practice
Practice happens on its own screen, one question at a time. Answers stay hidden until you submit yours, and you can stop and pick up at the same question later.
Start practisingCommon mistake. Students treat distance and displacement as always equal, ignoring direction changes. Always check whether the motion reverses direction, since displacement can be smaller than distance or even zero.
Your progress
Tick each step as you finish it. Your exact reading position is saved automatically, so Continue drops you back on the same line.
0 of 5 steps complete
Your place saves automatically as you read.