It took a crew 2 h. 40 min. to row 6km upstream and backagain. If the rate of flow of the stream was 3km/h, what wasthe rowing speed of the crew in still water?
pleitatsj1
Answered question
2022-08-02
It took a crew 2 h. 40 min. to row 6km upstream and backagain. If the rate of flow of the stream was 3km/h, what wasthe rowing speed of the crew in still water?
Answer & Explanation
Brennan Parks
Beginner2022-08-03Added 14 answers
Now to solve the equation, we apply the middle term factorization technique
so either (2x - 3) =0 or (x - 6) = 0 x =3/2 or x = 6 but x = rowing speed in still water be 3/2 km/h then in upstreamits velocity will be negative(3/2 - 3 = -3/2km/h) . so x = 6 Answer:- rowing speed in still water is = 6km/h
Dorsheele0p
Beginner2022-08-04Added 5 answers
Let x be the rowing speed in still water. When rowingupstream, the speed of current limits the movement of the boat.Thus, the effective speed of the crew while rowing upstream will be(x - 3) km/h. However when the crew rows downstream, thecurrent speed is added to the rowing speed. Thus, effective speedwill be (x + 3) km/h Since the crew takes 2 h. 40 min. or hours to row upstream and back, theequation for time can be modeled.
In order to solve this equation, remove the fractions bymultiplying using the least common denominator 3(x -3)(x + 3). Thus, we get the equation 18(x+3)+18(x-3)=8(x+3)(x-3). Remove the parentheses and simplify.
Bring all the terms to one side.
Factor.
(2x + 3)(x - 6) = 0 We get two equations using zero-factor property. 2x + 3 = 0 or x - 6 = 0 Solve for x to get two values; -3/2 and 6. Since speed cannever be negative, the value of x is 6. Thus, the rowingspeed of the boat is 6 km/h.