Question

Water in the Anacostia River near DC flows at an average rate of 1.55 feet per second. How many minutes would it take a raft floating on the river to travel one mile? (1mile = 5, 280feet)

Answer 1

57 minutes.

Explanation:

Knowing the equivalence between miles and feet, the first thing is to spend miles the speed they give us in feet.

1.55 ft / s * 1 mi / 5280 ft = 0.00029 mi / s

Now if we know that we want to travel a mile, we have that speed is the ratio between distance and time, therefore, time would be the ratio between distance and speed, like this:

t = d / v = 1 mi / (0.00029 mi / s) = 3406.45 s, how do you ask us in minutes, we know that one minute is equal to 60 seconds, like this:

3406.45 s * (1 min / 60 g) = 56.77 minutes.

Therefore it would take approximately 57 minutes.