Motion Flashcards – Cambridge IGCSE (9–1) Physics 0972 (Extended) (2026–2028)

How is constant speed $v$ calculated from distance travelled $s$ and time taken $t$?

$v = \frac{s}{t}$

What is one unit in which speed can be expressed?

Metres per second ($\mathrm{m/s}$).

How is average speed calculated for a journey with varying speed?

$\text{Average speed} = \frac{\text{total distance travelled}}{\text{total time taken}}$

Does the total time used to calculate average speed include time spent at rest?

Yes, time spent at rest is included.

What is velocity?

Speed in a given direction.

When can two objects with the same speed have different velocities?

When they move in different directions.

What does $g$ represent, and what is its approximate value and direction near Earth’s surface?

The approximately constant acceleration of free fall: $9.8\,\mathrm{m/s^2}$ downwards.

By approximately how much does a freely falling object’s speed increase each second near Earth’s surface?

By $9.8\,\mathrm{m/s}$ each second.

What assumption is made about air resistance in free fall?

Its effect is negligible.