Question

A car’s speedometer reads 20 m/s after accelerating, from a standing start, for 25s. What was the magnitude of its acceleration?

Answer 1

Explanation:

The units for velocity are distance/time and for acceleration distance/time^2 ( squared). (If this is unclear to you, it’s the change in velocity per unit time.) So what combination of 20 m/s and 25 s would have the units m/s^2?

(20 m/s) / 25 s

= 0.8 m/s^2

This is very small. An acceleration of 1 G is about 9.8 m/s^2.