Kinematic Equations of Motion
Kinematic equations of motion are formulae used to connect initial velocity, final velocity, acceleration, time, and displacement for uniformly accelerated motion.
Practice This ConceptMain explanation
Teacher explanation
The three common equations are v = u + at, s = ut + 1/2 at², and v² = u² + 2as. They should be used only when acceleration is uniform. The correct equation is chosen by checking which quantities are given and which quantity is required.
Example
If a scooter starts from rest and accelerates at 2 m/s² for 5 s, v = u + at = 0 + 2 × 5 = 10 m/s.
Simple analogy
Given, asked, formula, substitute, unit.
Common confusion
Students often use these equations even when acceleration is not uniform, or they choose an equation containing an unknown that is not needed.
Exam tip
Write u, v, a, t, and s before selecting the formula; this prevents most substitution mistakes.
Study the kinematic equations of motion diagram carefully
Use the labelled diagram to keep kinematic equations of motion clear in short answers and revision.
What this diagram makes clear
This diagram keeps the labels and direction of kinematic equations of motion in the right order.
Where this helps in exams
Use this for labelled diagram work and short exam answers on kinematic equations of motion.
Revision cue
Revise kinematic equations of motion through the labels before writing the answer.
Answer writing and exam use
1-mark use
Write the exact meaning of kinematic equations of motion in one clean line.
2-mark use
Define kinematic equations of motion and add one example or condition.
3-mark use
Explain kinematic equations of motion, show the method or example, and mention the common mistake.
Practice this concept with focused MCQs
Open the concept quiz intro first, review the test details, and then start a focused MCQ set from this concept only. Instant score and answer review are live now.
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