Question
Andre left his campsite and paddled to a fishing hole 1.5 km downstream. He timed his trip and found that it took him 9 min, His return trip upstream took him 22.5 min. Determine the speeed at which he paddled and the speed of the river? what steps did u use
Answers
9 min. = 0.15h, 22.5 min = 0.375h.
d = (Va+Vs)*t = 1.5 km.
(Va+Vs) * 0.15 = 1.5.
Eq1: Va + Vs = 10.
(Va-Vs)*0.375 = 1.5.
Eq2: Va - Vs = 4.
Add the two Eqs:
Va + Vs = 10.
Va - Vs = 4.
Sum: 2Va = 14, Va = 7 km/h.
In Eq1, replace Va with 7:
7 + Vs = 10 km/h, Vs = 3 km/h.
Va = Velocity of Andre.
Vs = Velocity of the stream.
d = (Va+Vs)*t = 1.5 km.
(Va+Vs) * 0.15 = 1.5.
Eq1: Va + Vs = 10.
(Va-Vs)*0.375 = 1.5.
Eq2: Va - Vs = 4.
Add the two Eqs:
Va + Vs = 10.
Va - Vs = 4.
Sum: 2Va = 14, Va = 7 km/h.
In Eq1, replace Va with 7:
7 + Vs = 10 km/h, Vs = 3 km/h.
Va = Velocity of Andre.
Vs = Velocity of the stream.