What is Uniform and varied motion? — Physics

Definition 40.4 Primary & Middle School Physics · Chapter 40 — Describing Motion: Trajectory and Speed

A motion is uniform when it covers equal distances in equal times — the steady walk of a metronome listener, the cruise of a train between stations. It is varied when the pace changes: speeding up (the sprinter off the blocks), slowing down (the bus braking), or both by turns (city traffic’s endless stop and go).

Three dotted films, one snapshot per tick: even spacing, spreading, crowding — uniform, accelerating, braking.

Examples

Example 40.7 (Speed by proportionality)

A tram in uniform motion covers $9\,\mathrm{km}$ in $20$ minutes. What speed is that, in the familiar kilometres-per-hour? Proportionality answers without any new machinery: an hour is three helpings of $20$ minutes, so the tram covers $3 \times 9 = 27\,\mathrm{km}$ in one hour — its speed is $27$ kilometres per hour. In a table:

minutes	$20$	$60$
kilometres	$9$	$27$

Uniform motion is proportionality between distance and time — your mathematics course and your physics course have just shaken hands.

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