1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
elixir [45]
3 years ago
6

A boat travels 2km upstream and 2km downstream. The total time of the trip is 1 hour. The speed of the stream is 2km/h. What is

the speed of the boat in still water?
Mathematics
1 answer:
scoray [572]3 years ago
7 0
2 = ( v + 2 ) × t1 ;
2 = ( v - 2 ) × t2 ;
t1 + t2 = 1 ;
where v is the speed of the boat in still water ; t1 is the time upstream ; t2 is the tome downstream ;
Then, v + 2 = 2 / t1 and v - 2 = 2 / t2 ;
v = 2 / t1   -  2  and v = 2 / t2  +  2 ;
2 / t1 - 2 = 2 / t2 + 2 ;
2 / t1 - 2 / t2 = 4 ;
1 / t1 - 1 / t2 = 2 ;
t2 - t1 = 2t1t2 ;
But, t2 = 1 - t1 ;
1 - t1 - t1 = 2t1( 1 - t1 ) ;
1 - 2t1 = 2t1 - 2t1^2 ;
2t1^2 - 4t1 + 1 = 0 ; quadratic equation ;
solving this equation , 
t1 ≈ 0.29 hour ;
v ≈ 2 / 0.29 - 2;
v ≈ 4.89 km/h ;

You might be interested in
Solve the following system by graphing and identify the point of intersection.
Viefleur [7K]

Answer: Option #1: ( -2 , -1 )

Step-by-step explanation:

5(-2) - (-1) = 9

(-2) - (-1) = -1

8 0
2 years ago
Solve the system of equations algebraically.<br><br> {Y=(x-2)^2+2<br> {Y+4=3x
nikdorinn [45]

Answer:

(5, 11) and (2, 2)

Step-by-step explanation:

y = (x-2)² + 2

y + 4 = 3x

(x-2)² + 2 + 4 = 3x

x² - 4x + 4 + 6 = 3x

x² - 7x + 10 = 0

(x - 5)(x - 2) = 0

x - 5 = 0, x = 5

x - 2 = 0, x = 2

y = (5-2)² + 2 = 11

(5, 11)

y = (2-2)² + 2 = 2

(2, 2)

5 0
3 years ago
Read 2 more answers
5=4b-12 hurry and make sure you put how you got the answer
PIT_PIT [208]

Answer:

4.25

Process:

  • 5=4b-12
  • 4b=12+5
  • 4b=17
  • b=\frac{17}{4}
  • b= 4.25
5 0
2 years ago
Read 2 more answers
PLEASE HELP ILL GIVE BRAINLIEST IF THE ANSWERS CORRECT
pickupchik [31]
The answer is 4 1/2 (four and a half).
5 0
1 year ago
Read 2 more answers
3in = Feet I need to understand how to convert this to fractions
Vinil7 [7]
A foot is 12 in so a fraction could be 3/12
8 0
3 years ago
Read 2 more answers
Other questions:
  • Find the coordinates of the center of the following circle. (x + 3)2 + (y - 6)2 = 24
    15·2 answers
  • In angle L M N the measure of angle L is equal to the measure of angle M. The measure of angle N is twice the measure of angle M
    11·1 answer
  • Polynomials 12y+3y + 2y + y²​
    9·2 answers
  • Which interval contains a local minimum for the graphed
    6·1 answer
  • Dianna has 7 quarters, 3 dimes, and 8 nickels in her purse. She reaches into her purse and randomly grabs two coins. What is the
    11·1 answer
  • Do anyone know how to do this problems ? Please help!
    14·1 answer
  • 1) Find the distance between -49.75 and 31.5 on a number line.​
    15·1 answer
  • The sum of 9 and a number is less than 12. Which of the following inequalities expresses the solutions ?
    14·1 answer
  • A woman who is 6ft tall is standing next to a flagpole. The shadow of the woman is 3.5ft and the shadow of the flagpole is 17.5f
    7·2 answers
  • 121. How much sand is needed to fill a sandbox
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!