Average speed
From /guides/what-physics-actually-is:
speed = distance / time. Units divide right alongside the numbers - km
divided by hours gives km/h, which is exactly what a speed should be measured
in. That's not a coincidence; it's your first free check that a formula is
built correctly.
The starter expression uses easy numbers - swap in this lesson's real ones.
Your task: a cyclist covers 150 km in 2.5 hours. Using
speed = distance / time, what's their average speed, in km/h?
You'll practice:
- Substituting real values into speed = distance / time
- Noticing that the units of your answer (km/h) confirm you divided, not multiplied
Related reading: Measurement and Units (Your Built-In Mistake Detector) →