A man can row a boat at 4kmhr in still water. He rows the boat 2km upstream and 2 km back to his starting place in 2 hours. How fast is the stream flowing

Answers

Answer 1

Answer:

2.83km/hr

Explanation:

Let stream flowing at the rat x km/hr

In still water

Speed of boat=4km/hr

Upstream speed=4-x

Downstream speed=4+x

Total time=2 hr

Time=Distance/speed

According to question

[tex]\frac{2}{4+x}+\frac{2}{4-x}=2[/tex]

[tex]\frac{8-2x+8+2x}{(4+x)(4-x)}=2[/tex]

[tex]\frac{16}{4^2-x^2}=2[/tex]

Using the formula

[tex](a+b)(a-b)=a^2-b^2[/tex]

[tex]4^2-x^2=\frac{16}{2}[/tex]

[tex]16-x^2=8[/tex]

[tex]16-8=x^2[/tex]

[tex]8=x^2[/tex]

[tex]x=\sqrt{8}=2.83km/hr[/tex]

Hence, the stream  is flowing at 2.83km/hr


Related Questions

A student is preparing to take a bath when she realizes the hot water tap in the bathroom is not working. The student goes to the kitchen and prepares 10 of 100°C water to mix with 10 L of 10°C water.

Answers

Answer:

(10 L)(100° C) + (90 L)(10°) = (100 L)T

1,000 + 900 = 100T

1,900 = 100T

100T = 1,900

T = 1,900/100

Explanation:

Which examples best demonstrate likely tasks for Legal Services workers? Check all that apply.

Cisco inspects an office building to make sure it meets fire safety regulations.
Gina gathers information about a court case.
Saul oversees inmates at a correctional facility.
Hana interviews and advises a person who has been accused of a crime.
Pamela pursues and arrests a person suspected of a crime.
Dewayne creates the paperwork for a business contract.

Answers

Answer:

b. d. f.

Explanation:

Got it right on Edge

Answer:

2. Gina gathers information about a court case.

4. Hana interviews and advises a person who has been accused of a crime.

6. Dewayne creates the paperwork for a business contract.

Need help ASAP
Will mark BRAINLIST and thanks only for correct answers

1.What is the correct way a cell phone call goes out?

-The phone call goes out, transmits through microwaves, then moves to the central hub. Then the signals go to the nearest tower to the receiver of the call.

-The phone call goes out, transmits through radio waves, then moves to the central hub. Then the signals go to the nearest tower to the receiver of the call.

-The phone call goes out, transmits through microwaves, then moves to the tower. Then the signals go to the nearest hub to the receiver of the call.

2.Which property of AM frequencies allow them to travel over long distances?

-high amplitude
-high energy
-constant velocity
-long wavelength

3.what types of waves do cell phones use?
-radio waves
-gamma rays
-microwaves

Answers

Answer:

1. The correct way a cell phone call goes out is;

The phone call goes out, transmits through radio waves, then moves to the central hub. Then the signal go to the nearest tower to the receiver of the call

2. Long wavelength

3. Microwave

Explanation:

1. When making a call through a cell phone, the speech made is digitized such that it is converted to electrical signals which are then converted into number strings that are transmitted out of the antenna of the phone as radio waves which are then picked up by the closest cellphone tower mast which then transmit the signal to the applicable central hub from where the signal is transmitted to the tower closest to the intended call receiver

Therefore, the correct option is that the phone call goes out, transmits through radio waves, then moves to the central hub. Then the signal go to the nearest tower to the receiver of the call

2. The property of AM frequencies that allow them to travel over long distances is long wavelength

The frequency of AM radio waves is between 540 kHz and 1600 kHz, which can be propagated as ground wave or by the ionosphere at night

3. Cell phones makes use of the subcategory of microwave which is the super high frequency (SHF) band which with a range of 3 GHz to 30 GHz

what is gas pressure

Answers

Gas pressure is caused when gas particles hit the walls of their container. The more often the particles hit the walls, and the faster they are moving when they do this, the higher the pressure. This is why the pressure in a tyre or balloon goes up when more air is pumped in. Hope this helps :)
gas pressure is when gas particles hit the wall of their container, the faster they hit the walls the higher the pressure

Part C
How many combined bits of storage are there on the two tablets?

Answers

Answer:

IVE BEEN TRYNA FIND THE ANSWER FOR THE PAST HOUR T-T

Explanation:

Answer:

3.2 x10^11 bits of storage

Explanation:

what are the laws of motion

Answers

The laws describe the relationship of an object and the forces acting on it

Two lasers are shining on a double slit, with slit separation d. Laser 1 has a wavelength of d/20, whereas laser 2 has a wavelength of d/15. The lasers produce separate interference patterns on a screen a distance 4.60 mm away from the slits.

A) Which laser has its first maximum closer to the central maximum?

B) What is the distance between the first maxima (on the same side of the central maximum) of the two patterns?

Answers

Answer:

A. Laser 1 has its first maximum closer to the central maximum.

B. 0.077 mm

Explanation:

A) Which laser has its first maximum closer to the central maximum?

Since for a double slit interference, sinθ = mλ/d where θ is the angle between the central axis and the maximum point, m = order of fringe, λ = wavelength of light and d = width of slit.

Also tanθ = y/D where θ is the angle between the central axis and the maximum point, y = distance between maximum point and central axis and D = distance between slit and screen = 4.60 mm.

Since θ is small,  sinθ ≅  θ and  tanθ ≅ θ

So, sinθ ≅ tanθ  

mλ/d = y/D

So, y = mλD/d for the first maximum, m = 1.

So,  y = (1)λD/d

y = λD/d

For the Laser 1, λ = d/20

So, y = λD/d

y = (d/20)D/d  

y = D/20

y = 4.60 mm/20

y = 0.23 mm

For the Laser 2, λ' = d/15

So, y' = λ'D/d

y' = (d/15)D/d  

y' = D/15

y' = 4.60 mm/15

y' = 0.307 mm

Since y = 0.23 mm < y' = 0.307 mm, Laser 1 has its first maximum closer to the central maximum.

B) What is the distance between the first maxima (on the same side of the central maximum) of the two patterns?

The distance between the first maxima (on the same side of the central maximum) of the two patterns is Δy = y' - y = 0.307 mm - 0.23 mm = 0.077 mm

Determine the momentum of a system that consists of two objects. One object, m1, has a mass of 6 kg and a velocity of 13 m/s towards the east and a second object, m2, has a mass of 14 kg and a velocity of 7 m/s in that same direction.

Answers

Momentum = (mass) x (velocity)

Momentum m₁  =  (6 kg) x (13 m/s east)  =  78 kg-m/s east

Momentum m₂  =  (14 kg) x (7 m/s east)  =  98 kg-m/s east

Since they're both in exactly the same direction you can simply addum up to get their total momentum.  It's 176 kg-m/s east .

The  momentum of a system that consists of two objects should be 176 kg m/s on east hand side.

Calculation of the momentum:

Since we know that

Momentum = (mass) x (velocity)

So,

Momentum m₁  =  (6 kg) x (13 m/s east)  =  78 kg-m/s east

Momentum m₂  =  (14 kg) x (7 m/s east)  =  98 kg-m/s east

Since they are on same direction so the total momentum should be

= 78 + 98

= 176 kg-m/s east

hence, The  momentum of a system that consists of two objects should be 176 kg m/s on east hand side.

Learn more about momentum here: https://brainly.com/question/24815698

what is electric switch​

Answers

Answer:

A device that is used to break an electric circuit is called electric switch

PLEASE HELP ASAP!!!!
Sort the statements based on whether they are correct or incorrect.
All waves have the same
wavelength.
Radio telescopes give us
information about the
birthplace of a star.
If the wavelength of a wave
increases, its frequency
also increases.
Visible light is a kind of
electromagnetic wave.
All objects emit
electromagnetic waves.

Answers

Answer: the first is incorrect the second is correct the third is correct

Explanation: the fourth is correct the fifth is incorrect

A body at rest is given an instal
uniform acceleration of 8.0m/s² for 30
seconds after which the acceleration is
reduced at 50m/s² for the next 20
second the body maintains the speed
attain for 60 seconds after which it is
brought to rest in 20 seconds​

Answers

Hrhhfbfbjfjfh high rn fbfhhfhfh gg f

v=u+at

v=0+8.0×30

v=240

a bear scratches his claws on a big pine tree. Does the bear do work on the tree? why or why not?


(btw it has to do with physics) ITS NOT A GENERAL QUESTION.

Answers

Answer:

See the explanation below.

Explanation:

Work in physics is defined as the product of force by the distance that the body travels in the direction of the force.

It can be represented by means of the following equation.

[tex]W=F*d[/tex]

where:

W = work [J]

F = force [N]

d = distance [m]

In the given example the work is zero since the tree does not move, therefore the bear exerts a force on the tree. But there is no talk of movement of the tree, therefore the work is zero.

how do you fix a broken foot
my sister is in literal tears and i dont have a phone and
our parents are out of the house rn

Answers

Go to your neighbor house and calll the hospital they’ll help or you can call your parent’s

As the Sun ages, what will happen to life here on Earth? Why?

Answers

Answer:

As the Sun ages it will enter another stage of stellar evolution where it's atmosphere begins to inflate.As the Sun heats up and expands, life on Earth will become increasingly difficult. Long before the Sun becomes a red giant some 4 or 5 billion years from now, our planet will be rendered uninhabitable.

~I HOPE IT HELPS♡

what kind of waves travel as transverse waves
A. Only mechanical
B. All waves
C. Some waves
D. No waves

Answers

Answer:

C. Some waves

Explanation:

The answer is some waves because transverse waves are not the only types of waves we have on the earth. We also have longlitudal waves, which means only some waves can only be transverse. The answer to the question should be C. Some waves.

How much does a crate weigh (force) if it is 0.25 meters wide and 1.5 meters long and it
exerts 800 pascals of pressure on the ground when it lands?

Answers

Force of a crate : 300 N

Further explanation

Given

0.25 meters wide and 1.5 meters long

Pressure = 800 Pa

Required

Force

Solution

P = F/A

A = 0.25 x 1.5

A = 0.375 m²

P = 800 Pa = 800 N/m²

Input the value :

F = P x A

F = 800 N/m² x 0.375 m²

F = 300 N

A boat travels 90 m in 10 seconds, what is its speed?
90 m/s
9 mi/hr
9 m/s
900 m/s

Answers

Answer:

it is 9m/s , hope it helps

Which one of the following is NOT a phenotype?
O Red Hair
O Brown Eyes
O Red/Green Blood
O Five foot tall girl
O These are all phenotypes

Answers

These are all phenotypes
red green blood ? (Sorry if i get it wrong)

98. In Fig. 24-71, a metal sphere

with charge q = 5.00 uC and radius

r = 3.00 cm is concentric with a

larger metal sphere with charge Q =

15.0 uC and radius R = 6.00 cm. (a)

What is the potential difference be-

tween the spheres? If we connect the

spheres with a wire, what then is the

charge on (b) the smaller sphere and

(c) the larger sphere?

Answers

Answer:

(a) The potential difference between the spheres is 750 kVA

(b) The charge on the smaller sphere is 6.[tex]\overline 6[/tex] μC

(c) The charge on the smaller sphere, Q₁ = 13.[tex]\overline 3[/tex] μC

Explanation:

(a) The given parameters are;

The charge on the inner sphere, q = 5.00 μC

The radius of the inner sphere, r = 3.00 cm = 0.03 m

The charge on the larger sphere, Q = 15.0 μμC

The radius of the larger sphere, R = 6.00 cm = 0.06 m

The potential difference between two concentric spheres is given according to the following equation;

[tex]V_r - V_R = k \times q \times \left ( \dfrac{1}{r} - \dfrac{1}{R} \right)[/tex]

Where;

R = The radius of the larger sphere = 0.06 m

r = The radius of the inner sphere = 0.03 m

q = The charge of the inner sphere = 5.00 × 10⁻⁶ C

Q = The charge of the outer sphere = 15.00 × 10⁻⁶ C

k = 9 × 10⁹ N·m²/C²

Therefore, by plugging in the value of the variables, we have;

[tex]V_r - V_R = 9 \times 10^9 \times 5.00 \times 10^{-6} \times \left ( \dfrac{1}{0.03} - \dfrac{1}{0.06} \right) = 750,000[/tex]

The potential difference between the spheres, [tex]V_r - V_R[/tex] = 750,000 N·m/C = 750 kVA

(b) When the spheres are connected with a wire, the charge, 'q', on the smaller sphere will be added to the charge, 'Q', on the larger sphere which as follows;

[tex]Q_f[/tex] = Q + q = (5 + 15) × 10⁻⁶ C = 20 × 10⁻⁶ C

[tex]Q_f[/tex] = 20 × 10⁻⁶ C

From which we have;

Q₁/Q₂ = R/r

Where;

Q₁ = The new charge on the on the larger sphere

Q₂ = The new charge on the on the smaller sphere

[tex]Q_f[/tex] = 20 × 10⁻⁶ C = Q₁ + Q₂

∴ Q₁ = 20 × 10⁻⁶ C - Q₂ = 20 μC - Q₂

∴ (20 μC - Q₂)/Q₂ = 0.06/(0.03) = 2

20 μC - Q₂ = 2·Q₂

20 μC = 3·Q₂

Q₂ = 20 μC/3

The charge on the smaller sphere, Q₂ = 20 μC/3 = 6.[tex]\overline 6[/tex] μC

(c) Q₁ = 20 μC - Q₂ = 20 μC - 20 μC/3 = 40 μC/3

The charge on the smaller sphere, Q₁ = 40 μC/3 = 13.[tex]\overline 3[/tex] μC.

The potential difference is 7.5*10^5V and the charge on the smaller sphere is 6.67uC while the charge on the larger sphere is 13.34uC

Data;

q = 5.0 uCr = 3.0cm= 0.03mQ = 15.0uCR = 6.0cm = 0.06m

Potential Difference between the Spheres

for the inner sphere;

[tex]v_i = \frac{kq}{r} = \frac{(9*10^9)(5*10^-^6)}{0.03} \\v_i = 1.5*10^6V[/tex]

for the outer sphere;

[tex]v_o = \frac{KQ}{R} = \frac{(9*10^9)(15*10^-^6)}{0.06} = 2.25 * 10^6V[/tex]

The difference in potential is

[tex]\delta V = v_o - v_i = 2.25*10^6 - 1.5*10^6 = 7.5*10^5V[/tex]

Charge on the Smaller Plate

[tex]q + Q = 5 + 15 = 20 \mu C = 20*10^-^6C ..eq(i)[/tex]

The sharing of charge continues till they attain a point of equal potential

[tex]v_i = v_o \\\frac{kq}{r} = \frac{kQ}{R} \\\frac{q}{0.03} = \frac{Q}{0.06} \\Q= 2q ...eq(ii)\\[/tex]

let's solve for equation (i) and equation (ii)

[tex]q+2q = 20\mu C\\q = 6.67 \mu C[/tex]

The charge on the smaller sphere is 6.67uC

The charge on the larger sphere

The charge on the larger sphere is

[tex]Q = 2q\\q = 6.67 \mu C\\Q = 2 * 6.67 = 13.34 \mu C[/tex]

The charge on the larger sphere is 13.34uC

Learn more on potential difference on a charged particle here;

https://brainly.com/question/9383604

Please Help Fast Select the correct answer. Which equation correctly relates kinetic energy, mass, and velocity? A. B. C. D.

Answers

Answer:

KE = 1/2 m v^2

Explanation:

which of the following cannot be used for measurement of time

a A leaking tap

b simple pendulum

c shadow of object during the day

d blinking of eyes ​

Answers

Answer:

D. blinking ofeyea

Explanation:

not really sure

What force will accelerate a 20 kg object at 4 m/s 2? *

Answers

Answer:

80 N

Explanation:

mass = 20 kg

acceleration = 4 m/s^2

Force = mass * acceleration

         = 20 *4  

         = 80 N

Think about a situation at school where you or someone you know
has demonstrated grit. Describe the situation. Pls help me

Answers

Answer:

to have courage and show the strength of your character. ... A person with true grit has passion and perseverance. Goals are set and followed through.

Explanation:

for example: i had the passion and the courage to finish my school work and chores for i can go out with my friends and to get out of the house for a bit and have fun so i had the courage to finish chores from the house and do some schoolwork for i can finish ad hang out with some friends. so i had the strength to finish everything because i didn't want to be doing school work and chores any more so i had the passion to finish up quickly  

Read through the and calculate the predicted change in kinetic energy of the oblect compared to 50 kg ball traveling at 10 m/s . 50 kg ball traveling at 20 n / s would havekinetic energy 50 kg traveling at 5 m/s would have energy 50 kg person falling at 10 m/s would havekinetic energy

Answers

Answer:

A 50 kg ball traveling at 20 m/s would have 4 times more kinetic energy.

A 50 kg ball traveling at 5 m/s would have 4 times less kinetic energy.

A 50 kg person falling at 10 m/s would have the same kinetic energy.

Explanation:

hope this helps:)


If the small piston has an area of .004 square
meters and Bob pushes down on it with 225 N of
force, what is the magnitude of the pressure
increase in the system?

Answers

The magnitude of the pressure : P = 56,250 N/m

Further explanation

Given

Area of 0.004 m²

Force 225 N

Required

the magnitude of the pressure

Solution

Pressure = force exerted per unit of surface area(perpendicular)

Can be formulated :

P = F/A

Input the value :

P = 225 N / 0.004 m

P = 56,250 N/m

James is planning a science fair project on sound waves. He places an alarm inside a jar which he can remove the
air from. Before he removes the air, he can hear the alarm ringing. After he removes the alr, he cannot hear the
alarm ringing. What condusion can you draw from this experiment?


A. Sound waves can travel in a vacuum
B. Sound waves are transverse waves and are loud
C. Sound waves cannot travel through a medium
D. Sound waves require a medium to travel through

Answers

Answer: c

Explanation:

Sound waves cannot travel through a medium

how much potential energy does the ball have when it reaches the top of its ascent​

Answers

PE = 450 m

Further explanation

Given

The initial problem might be like this

A 1.0-kg ball is thrown into the air with an initial velocity of 30 m/s.

Required

Potential energy

Solution

h max = vo²sin²θ/2g

h max = 30²sin²90/2.10

h max = 45 m

PE = m.g.h

PE = 1 x 10 x 45

PE = 450 m

1
AI
A3
If A1 = 27A and A3 = 1.9A, what would A2 read?

Answers

Answer:

0.8A

Explanation:

because im very intelligent and beautiful so the answer is correct and its 0.8A

V,? = V2 + 2a Ax
1. A toy car increases velocity over a displacement of 15.2 m. If
the car starts at rest and has a final velocity of 0.76 m/s, what
is the magnitude of its acceleration?

Answers

Answer:

Explanation:

[tex]V^2=V^2_i+2a(x_f-x_i)[/tex]

[tex]0.76^2=0^2+2a(15.2)[/tex]

[tex]0.5776=30.4a[/tex]

[tex]a=0.019m/s^2[/tex]

how find \empirical formula

Answers

the empirical formula of a chemical compound is the simplest positive integer ratio of atoms present in a compound. A simple example of this concept is that the empirical formula of sulfur monoxide, or SO, would simply be SO, as is the empirical formula of disulfur dioxide, S₂O₂. Thus, sulfur monoxide and disulfur dioxide, both compounds of sulphur and oxygen, have the same empirical formula. However, their molecular formulas, which express the number of atoms in each molecule of a chemical compound, are not the same.
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