At a starting point, Mark walks south at a rate of 1ft per second, while Sam walks east at a rate of 1.5 feet per second. How fast are they walking away from each other after 1 minute?

Question

At a starting point, Mark walks south at a rate of 1ft per second, while Sam walks east at a rate of 1.5 feet per second. How fast are they walking away from each other after 1 minute?

Answer 1

After a time t seconds,

Mark will have walked 1×t ft, and

Sam will have walked 1.5×t ft.

Their distance will be

√(t² + (1.5t)²) = 1.8t

Thus their distance increases at the constant rate of 1.8 ft/2.

That is how fast they are walking away from each other after 1 minute, as well as at every other instant.