Mathematics, 02.02.2020 04:43 AyeSmoky

For the following problem:
(a) identify the unknown quantities and introduce variables to represent them
(b) write equations which express the information given in the statement of the problem
(c) solve the equations and give the answer

amelia swam 12 kilometres upstream in 6 hours. the return trip downstream took 2 hours. find the speed of the current in the river

Answers: 1

Show answers

Answers

Answer from: carebear147

(a) identify the unknown quantities and introduce variables to represent them

Distance traveled by Amelia upstream is 12 km. Let us call it x.

So that x = 12 km

Distance traveled downstream is unknown. But by reading and understanding the question, one can tell that the distance covered on trip downstream must be the same as distance traveled while going upstream.

Let us call it y.

So that y = x = 12 km

y = 12 km

Speed of Amelia while swimming = s

Speed of the current in the river = c

(b) write equations which express the information given in the statement of the problem

s - c = 2 ------eq-1

s + c = 6 ------eq-2

Step-by-step explanation:

Speed of Amelia's swimming is same then why is the time taken while going upstream different than while going downstream?

It is because the resistance of current in the river is in the downward direction. It explains why Amelia takes more time to go upstairs and much less to come back.

Using Speed = Distance traveled/Time

While going upstream:

Amelia is going against the current, hence the direction for Amelia and river's current is opposite. We get the equation:

s - c = 12/6 = 2------eq-1 where t = 6 hours

While going downstream:

Amelia is going with the current, hence the direction for Amelia and river's current is same. We get the equation:

s + c = 12/2 = 6------eq-2 where t = 2 hours

speed of the current in the river = c = 4 km/h

Step-by-step explanation:

To find = c?

We will use the two equations:

s - c = 2 ------eq-1

s + c = 6 ------eq-2

From eq-1 :

$s-c= 2\\⇒ s = 2+c\\$

putting s = 2+c in eq-2:

$(2+c)+c = 6\\2+2c=6\\2c=8\\c=4$

Hence; the speed of the current of the river is 4 km/h.

Answer from: Quest

You have to put the answer options on here in order for us to know which statement to tell you is correct.

Answer from: Quest

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6

These figures are similar. the perimeter and area of one are given. the perimeter of the other is al

Another question on Mathematics

Mathematics, 21.06.2019 12:30

Last saturday, the museum box office sold 281 tickets for a total of $3,954. adults ticket cost $15, and students ticket cost $12. how many of each kind of tickets were sold?

Answers: 1

Answer

Mathematics, 21.06.2019 19:00

Amodel rocket is launched from a roof into a large field. the path of the rocket can be modeled by the equation y = -0.04x^2 + 8.6x + 4.8, where x is the horizontal distance, in meters, from the starting point on the roof and y is the height, in meters, of the rocket above the ground. how far horizontally from its starting point will the rocket land? a. 0.56 m b. 215.56 m c. 431.11 m d. 215.74 m

Answers: 1

Answer

Mathematics, 21.06.2019 23:00

Car a and car b were in a race .the driver of car b claimed that his car was twice as fast as car a

Answers: 3

Answer

Mathematics, 21.06.2019 23:10

Which expression is equivalent to -12(3x-3/4)

Answers: 2

Answer

You know the right answer?

For the following problem:
(a) identify the unknown quantities and introduce variables to rep...