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

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

Brennan Parks

Beginner2022-08-03Added 14 answers

Now to solve the equation, 2 x 2 9 x 18 = 0 we apply the middle term factorization technique
2 x 2 9 x 18 = 0
2 x 2 12 x + 3 x 18 = 0
2 x ( x 6 ) + 3 ( x 6 ) = 0
( 2 x 3 ) ( x 6 ) = 0
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

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 8 3 hours to row upstream and back, theequation for time can be modeled.
6 x 3 + 6 x + 3 = 8 3
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.
18 x + 54 + 18 x 54 = 8 x 2 72
36 x = 8 x 2 72
Bring all the terms to one side.
8 x 2 36 x 72 = 0
Factor.
2 x 2 9 x 18 = 0
(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.

Do you have a similar question?

Recalculate according to your conditions!

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?