Question

Question content area top Part 1 A motorboat maintained a constant speed of 13 miles per hour relative to the water in going 22 miles upstream and then returning. The total time for the trip was 6.5 hours. Use this information to find the speed of the current.

Answer 1

Explanation:

Rate upstream = b -w b = boat speed w = water speed

Rate downstream = b+w distance is given as 22 miles

distance / rate = time

22/ (b-w) + 22 / ( b+w) = 6.5 multiply the entire equation by (b+w)(b-w) :

22(b+w) + 22 (b-w) = 6.5 ( b+w)(b-w)

44b = 6.5 b^2 - 6.5w^2 re-arrange

6.5 w^2 = 6.5 b^2 - 44b we know b = 13 (given) solve for w

6.5 w^2 = 526.5

w = 9 m/hr