Question

A runner is jogging at a steady 6.2 km/hr. When the runner is 4.9 km from the finish line, a bird begins flying from the runner to the finish line at 24.8 km/hr (4 times as fast as the runner). When the bird reaches the finish line, it turns around and flies back to the runner.


Shape


How far does the bird travel? Even though the bird is a dodo, assume that it occupies only one point in space (a “zero” length bird) and that it can turn without loss of speed. Answer in units of km.

Answer 1

design a mod 12 counter.

Answer 2

first, dodos do not fly.
second, dodos are extinct.

However, since time=distance/speed, if the bird flies back x km, then

(4.9+x)/24.8 = (4.9-x)/6.2
x = 2.94

So, the bird flew 7.84 km

Answer 3

How'd you get 7.84?