The Speed of Things

Imagine a car traveling at 60 km/h. If the journey is 120 km long, how long does it take to arrive?

At 60 km/h over 120 km, the trip takes 2.0 hours — or roughly 120 minutes.

That's the fundamental relationship: time = distance / speed. Drag the sliders above and watch how the numbers in this paragraph respond. Every reactive element shares the same state, no matter how far apart they are in the text.

Why this matters

Traditional writing forces you to pick one set of numbers and stick with them. But ideas about relationships — how one quantity affects another — are better shown than told. When you can slide "speed" from 60 km/h down to 10 km/h and feel the travel time stretch, the relationship clicks in a way that static text never achieves.