RATE, DISTANCE, TIME
posted by CINDY on .
TIM PADDLED HIS KAYAK 12 KM UPSTREAM AGAINST A 3 KM/H CURRENT AND BACK AGAIN IN 5 HR 20 MINUTES. iN THAT TIME
HOW FAR COULD HE HAVE PADDLED IN STILL WATER
12/(v+3) + 12/(v-3) = 5.33 hours
Solve for this speed in still water, v.
12(v-3) + 12(v+3) = 5.33 (v^2 -9)
24 v = 5.33 v^2 - 48
Use the quadratic equation and take the positive root for v.
v = 6.0 km/h
In the same time, the distance he could travel in still water is
D = 5.33 * v = 32 km