A motorboat, whose speed in still water is 15 km/hour, traveled with the current of a river for 35 km, and against the current for 25 km. the boat took the same time traveling with the current as it did traveling against the current. what is the speed of the current in the river?

Answers

Answer 1

Let's call v=15 km/h the speed of the boat in still water, and c the speed of the current.
When the boat travels with the current, its total speed is (v+c), and it travels for a distance of 35 km in a time t. When the boat travels against the current, its total speed is (v-c), and it travels for a distance of 25 km in the same time t. We can write the basic relationship of the uniform linear motion [tex]S=vt[/tex] for both situations:
[tex]35 km = (v+c)t[/tex]
[tex]25 km=(v-c)t[/tex]
If we divide the first equation by the second one, we find
[tex] \frac{35}{25}= \frac{v+c}{v-c} [/tex]
and by rearranging this, we can find the value of c, the speed of the current:
[tex]c= \frac{1}{6}v= \frac{1}{6}(15 km/h)=2.5 km/h [/tex]

Related Questions

The mass of a full bottle of cooking oil is 1.30 kg when half Is empty calculate mass of empty bottle

Answers

Mass of bottle + cooking oil = 1.3 kg
Mass of bottle + 1/2 cooking oil = 0.9 kg
Thus half cooking oil = 1.3 - 0.9
= 0.4 kg
Mass of cooking oil in a full bottle = 0.4 × 2
= 0.8 kg
Therefore the mass of the empty bottle
= 1.3 - 0.8
= 0.5 kg

The temperature differences seen between quito, ecuador, and guayaquil, ecuador, illustrate the effect of _____. ocean currents cloud cover altitude

Answers

The answer would be altitude.
Quito has the altitude of 2.850m, while Guayaquil has the altitude of 5m.
This can lead to the vast difference in climates.
The most noticeable difference is that temperature drop with increased altitude.
For each 1,000 foot rise in altitude, there is a 4°F drop in temperature.

This one has got to be the altitude.

What term describes an energy resource that can be used up?

Answers

Answer:
non-renewable energy resources are the ones that can be used up

Explanation:
Energy resources can be classified into two categories:
1- non renewable resources: these are the energy resources that cannot renew themselves. They are the resources that are formed from sources that can be consumed and run out. All fossil fuels are considered non renewable resources
Examples of non renewable energy resources: coal, oil, gas, petroleum , ......

2- renewable resources: these are the energy resources that are always present and can easily be renewed. Therefore, they do not come to an end.
Examples of renewable resources: solar energy, wind energy,.....

Based on the above, the energy resource that can be used up is the non renewable energy resource.

Hope this helps :)

Answer:

Non-renewable resource

Explanation:

There are two types energy resources.

1. Renewable resource: The resource of energy which is present in abundant quantity and replenishes itself in nature.

For example: solar energy, wind energy etc.

2. Non-renewable- The resource of energy which is present in limited quantity and does it takes millions of years to replenish. It can be used up. For example: Coal, oil and gas.

A strong magnetic field surrounds earth. How does earths magnetic feild help humans?

Answers

Answer:

Earth's magnetic field deviates high energy particles (e.g cosmic rays) that are a risk for human health.

Explanation:

Cosmic rays are high energy charged particles (88% protons, 10% nuclei of helium, 1% heavier nuclei) that came from the outer space. The energies of these particles are in the range of 1 GeV to 10⁸ TeV. Since they are charged particles, they will be deviated by Earth’s magnetic field¹ (as a reminder: A magnetic field applies a magnetic force over a moving charged particle).

Earth’s magnetic field works as a shield to humans against high energy charged particles, if cosmic rays were in touch with a human body, it can break molecules that forms DNA structure². Modifying that structure can lead to diseases as cancer, for example.

Units:

GeV: Giga-electronvolt

TeV: Tera-electronvolt

¹Magnetic field: It is generated around the space of a moving charged particle.

²DNA structure: It is a compound of different molecules that provides information to cells functionality.

Match the term to its definition. A. Conduction Heat flowing when a liquid or gas carries the heat B. Convection Heat flowing between two objects that are touching each other C. Radiation Heat flowing in waves

Answers

A. Conduction --> Heat flowing between two objects that are touching each other
B. Convection --> Heat flowing when a liquid or gas carries the heat
C. Radiation --> Heat flowing in waves

When you look into a clear pond, a fish may appear to be in a different position than it actually is. What is this caused by?

A. diffraction

B. dispersion

C. refraction

D. reflection,

Answers

Refraction Refraction is when waves are deflected when passing obliquely through the interface between one medium and another or through a medium of varying density. (the pond water)

Select all that apply. A hypothesis is _____. always correct determined before experimentation begins the experimental factor that changes in response to a change in the independent variable testable and falsifiable

Answers

Final answer:

A hypothesis is a testable and falsifiable assumption known before experimentation. It's not always correct and does not always change in response to a change in the independent variable. Even when experiments support a hypothesis, it is not confirmed as absolutely correct.

Explanation:

A hypothesis is a testable and falsifiable assumption based on what is known. It is determined before any experiment begins and serves as a guide for the collection and analysis of data. For instance, we could formulate a hypothesis like, 'If I water plants with sugar-mixed water, they will grow faster.'. If subsequent experimentation disproves this hypothesis, it must be discarded or reformed.

A hypothesis does not necessarily change in response to a change in the independent variable; rather, it predicts the expected response or outcome. However, a hypothesis is not always correct. It represents our best prediction based on the current information and can often be proven wrong as new data or insights become available via further empirical research.

Furthermore, in scientific research, even though a hypothesis is supported by multiple experiments, it does not confirm it to be correct, as future experiments could contradict it. Also, if a hypothesis explains a large amount of experimental data it could be considered a theory, but even theories can be modified if new data appears.

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Which of the following items is most sensitive to increased acidity in the environment?

Answers

concrete buildings. i hope this helps you

Answer: CONCRETE BUILDINGS

Explanation:

i got it right in my quiz

Match the description of how heat is transferred to the proper term. A. When two things in contact with each other transfer heat Convection B. When a liquid or gas carries heat Conduction C. When waves transfer heat Radiation

Answers

When two things in contact with each other transfer heat - Conduction
When a liquid or has carries heat- Convection
When waves transfer heat- Radiation

these are my answers from the quiz i took

Which are ways of showing probability? Check all that apply.

Answers

i would say

-50%

-3/4

-25%

-7/8

Answer: a c e f

Explanation:

An experiment is designed to test the relationship between the initial height of a basketball before it is dropped to the height of its rebound bounce. The height of the rebound bounce is measured using a scale positioned behind the ball.

In the above experiment, which condition would not be controlled?

Answers

In general, when designing the experiment, it is desirable to control all thing that can affect the outcome of the experiment. In practice, this is not easily obtainable.
I imagine it would be hard to control the temperature in this experiment. Even though, temperature does affect the ball's bounce.
Keep in mind that even if you don't control something it still can be measured and then you can use that information to correct your predictions.

In general, when coming up with the experiment, it's fascinating to control all factor which will have an effect on the end result of the experiment. To observe, this is often not simply gettable.
I imagine it'd be hard to manage the temperature during this experiment. although, the temperature will have an effect on the ball's bounce.
Keep in mind that even if you do not management one thing it still is often measured then you'll be able to use that information to correct your predictions.
Explanation:

Now an uncontrolled variable is something like a force of nature, size of one thing or it's physically that cannot be controlled or modified.

An uncontrolled variable, or intermediator variable, is that the variable in an associate experiment that has the potential to negatively impact the link between the independent and dependent variables.

If the diameter of the black marble is 3.0 cm, and by using the formula for volume, what is a good approximation of its volume? Record to the ones place.
______cm3
Determine the initial volume of water in the graduated cylinder. If you added the black marble to the graduated cylinder and it sinks, what final volume should the water level indicate? Record to the ones place.
______ML

Answers

Answer:

The answers are 14 and 124, respectively.

Explanation:

The proof for these answers is the image attached.

Answer:

it is 14 and 124 I have took the test.

Explanation:

help me plzzzz i will give u a medal
Which statement best describes how light waves travel in a uniform medium?

A.
in straight lines

B.
in extending circles

C.
in bent lines

D.
in shrinking ripples,

Answers

Option A. In straight lines. In a uniform medium, the light waves travel in a straight line through a vacuum. These waves vary in lengths through a vacuum consisting of periodic oscillations of electric and magnetic fields that cause the particles that traverse the lines in the vacuum.

The answer is in straight lines

A vector has an x-component of length 10 and a y-component of length 3. What is the angle of the vector? (Hint: Use the inverse tangent.)

Answers

The vector, the x-component and the y-component form a rectangle triangle where the vector is the hypothenuse and the x and y components are the two sides.
Calling [tex]\alpha [/tex] the angle between the vector and the horizontal direction (x), the two sides are related to [tex]\alpha [/tex] by
[tex]\tan \alpha = \frac{v_y}{v_x} [/tex]
where vy and vx are the two components on the y- and x-axis. Using vx=10 and vy=3 we find
[tex]\tan \alpha = \frac{3}{10} =0.3[/tex]
And so the angle is
[tex]\alpha = \arctan (0.3)=16.7^{\circ}[/tex]

The input force of a pulley system must move 8.0 m to lift a 3,000-n engine a distance of 2.0 m. what is the ima of the system?

Answers

The IMA (ideal mechanical advantage) of a single pulley is the ratio between the output force and the input force:
[tex]IMA= \frac{F_{out}}{F_{in}} [/tex]
Moreover, for the law of conservation of energy, the work done in input to lift the lift must be equal to the output work:
[tex]W_{in}=W_{out}[/tex]
[tex]F_{in} d_{in}=F_{out} d_{out}[/tex]
where the [tex]d_{in}[/tex] is the distance for which the input force is applied while [tex]d_{out}[/tex] is the distance of which the lift is lifted.
Substituting [tex]F_{out}=3000 N[/tex], [tex]d_{out}=2 m[/tex] and [tex]d_{in}=8 m[/tex] into the previous equation, we find the value of the input force:
[tex]F_{in}= \frac{F_{out} d_{out}}{d_{in}} = \frac{(3000 N)(2 m)}{8 m}=750 N [/tex]
And now we can find the IMA of the pulley:
[tex]IMA= \frac{F_{out}}{F_{in}}= \frac{3000 N}{750 N}=4 [/tex]

As we can see, the IMA is also equal to the ratio between the input and output distance:
[tex]IMA= \frac{d_{in}}{F_{out}}= \frac{8m}{2m}=4 [/tex]

PART 2!!!! PLEASEEEE HELLLPPPP

Answers

I see three (3) question in the picture.
Here are the answers:

#1).
The total effective resistance of resistors in series is
the sum of the individuals.

(4 + 8 + 12) = 24 ohms.

Current = (voltage) / (resistance) = (24 V) / (24 ohms) = 1 Ampere.

#2).
To answer this question, we don't care what the
total effective resistance is.
The resistors are in parallel, so each one is connected
directly to the terminals of the battery, and each resistor
has 24 V across it.

Current through the 4-ohm resistor = (voltage) / (resistance)

= (24 V) / (4 ohms)

= 6 Amperes.

#3).
In a series circuit, the total effective resistance is
the sum of the individual resistors, and the current
is (battery voltage) / (total effective resistance).

If pone resistor is replaced with a resistor of lower resistance,
then the sum of the individuals is less, and the current in the
series circuit increases (if the battery can handle it).

How much heat is needed to change 5.42 grams of solid gold to liquid gold at its melting point of 1,063°C? The latent heat of fusion of gold is 66.6 J/g.

Answers

[tex]5.42 \times 66.6 = 360.972[/tex]
360.972 J

Answer:

360.97 J

Explanation:

mass of gold, m = 5.42 g

Latent heat of fusion, L = 66.6 J/g

The amount of heat required to convert 1 kg of solid into liquid state at its melting point is called latent heat.

L = Heat / mass

So, L = Q / m

Q = m L

Where, Q is the amount of heat supplied and L be latent heat of fusion amd m be the mass of substance.

Q = 5.42 x 66.6

Q = 360.97 J

Thus, the amount of heat required to melt the desired amount of gold is 360.97 J.

How was the speed of light measured in a precise way?

A. by timing how long it takes for an assistant far away to turn on a lantern after the scientist turns one on

B. by watching for eclipses

C. by timing the speed of falling meteorites

D. by using rotating mirrors to measure light's round trip travel to a distant mountain

:O :/,

Answers

The first successful measurement of the speed of light was done so through the observation of eclipses. Olaus Roemer noticed that depending on the relationship between the Earth, Sun and Jupiter there were varying differences in the times of predicted eclipses.

How does the mass relate to the momentum ?

Answers

Hi there!

Mass relates to momentum because
the heavier the object is, the more energy ît takes to make it start moving and make it stop. For example, if I had a 20 pound object and a 50 pound object, the 50 pound object would travel less than the 20 pound object when the same amount of force is exerted on it.

Hope this helps!

A driver in front of you is signaling with his or her hand and arm pointing upward this driver wants to

Answers

Go straight. The man wants to go straight on the road.

A balloon filled with helium occupies 20.0 l at 1.50 atm and 25.0◦
c. how many moles of helium will there be in the balloon at stp?

Answers

Final answer:

By applying the Ideal Gas Law, we find that the helium balloon contains approximately 1.22 moles under the given conditions. This mole amount remains consistent at standard temperature and pressure (STP) as no gas is added or removed.

Explanation:

Your question pertains to the concepts of chemical stoichiometry and the gas laws. Given the conditions and the volume of the gas, we start by converting the initial conditions to Standard Temperature and Pressure (STP). Your balloon containing helium is at a volume of 20.0 L, a pressure of 1.50 atm, and a temperature of 25.0°C (or 298.15 K in absolute temperature).

The Ideal Gas Law (PV=nRT) allows us to calculate the number of moles (n) in the balloon initially: n = PV/RT = (1.50 atm * 20.0 L) / (0.0821 L*atm/mol*K * 298.15 K) which results in approximately 1.22 mol of helium.

Now, to find the number of moles at STP, we need to remember that the number of moles remains the same as long as no gas is added or removed. Therefore, your balloon contains approximately 1.22 moles of helium at STP as well.

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There are approximately [tex]1.225\ moles[/tex] of helium in the balloon at STP (Standard Temperature and Pressure).

To find out how many moles of helium are in the balloon at STP (Standard Temperature and Pressure), we'll follow these steps:

Given Data

Volume of the balloon, [tex]$ V = 20.0 $ L[/tex]

Pressure of the helium gas,[tex]$ P = 1.50 $ atm[/tex]

Temperature of the helium gas, [tex]$ T = 25.0 $ ^\circ C[/tex]

Convert Temperature to Kelvin

First, convert the temperature from Celsius to Kelvin:

[tex]\[ T_{\text{Kelvin}} = T_{\text{Celsius}} + 273.15 \][/tex]

[tex]\[ T_{\text{Kelvin}} = 25.0^\circ C} + 273.15 \][/tex]

[tex]\[ T_{\text{Kelvin}} = 298.15 \text{ K} \][/tex]

Calculate the Number of Moles (using the Ideal Gas Law)

The ideal gas law equation relates the pressure, volume, temperature, and number of moles [tex]($ n $)[/tex] of a gas:

[tex]\[ PV = nRT \][/tex]

where:

[tex]$ P $[/tex] is the pressure in atmospheres (atm)

[tex]$ V $[/tex] is the volume in liters ([tex]L[/tex])

[tex]$ n $[/tex] is the number of moles of gas

[tex]$ R $[/tex] is the ideal gas constant, [tex]$ R = 0.0821 $ L\ atm/mol\ K[/tex]

[tex]$ T $[/tex] is the temperature in Kelvin ([tex]K[/tex])

First, calculate [tex]$ n $[/tex] using the ideal gas law:

[tex]\[ n = \frac{PV}{RT} \][/tex]

Now, substitute the given values:

[tex]\[ n = \frac{(1.50 \text{ atm}) \times (20.0 \text{ L})}{(0.0821 \text{ L·atm/mol·K}) \times (298.15 \text{ K})} \][/tex]

[tex]\[ n = \frac{30.0 \text{ atm·L}}{24.485 \text{ L·atm/mol}} \][/tex]

[tex]\[ n = 1.225 \text{ mol} \][/tex]

A very small object with mass 6.90 × 10^−9 kg and positive charge 8.30 × 10^−9 C is projected directly toward a very large insulating sheet of positive charge that has uniform surface charge density 5.90 x 10^-8 C/m^2. The object is initially 0.530 m from the sheet.

What initial speed must the object have in order for its closest distance of approach to the sheet to be 0.170 m ?,

Answers

Mass of the object m = 6.90 × 10^−9 kg Charge of the object Q = 8.30 × 10^−9 C Surface charge density = 5.90 x 10^-8 C/m^2 Distance d1 = 0.530 m, d2 = 0.170 m Kinetic energy KE = 1/2 mv^2 Work = F x d = electric field x q x d => E x 8.30 × 10^−9 x (0.530 - 0.170) Following the energy conversion principles, 1/2 x 6.90 × 10^−9 x v^2 = E x 8.30 × 10^−9 x (0.530 - 0.170) 3.45 x v^2 = 8.30 x 0.36 x E => 3.45v^2 = 3E calculating the electric field E = 5.90 x 10^-8 / ( 2 x 8.85 x 10^-12) = 3333 So 3.45v^2 = 3 x 3333 => v^2 = 9999 / 3.45 => v^2 = 2898 => v = 53.8 m/s Intial speed v = 53.8 m/s

The potential difference in a simple circuit is 9 v and the resistance is 47 ω . what current flows in the circuit? answer in units of
a.

Answers

The current flowing in the circuit with a potential difference of 9 volts and resistance of 47 ohms is approximately 0.1915 amperes (A), calculated using Ohm's Law (I = V/R).

The current that flows through a circuit can be calculated using Ohm's Law, which is given by the formula V = IR, where V is the potential difference, I is the current, and R is the resistance. In this case, the potential difference is 9 volts (V) and the resistance is 47 ohms (Ω). To find the current, we rearrange the formula to I = V/R.

Substitute the given values into the formula:

I = 9V / 47Ω

I ≈ 0.1915 A

So the current flowing in the circuit is approximately 0.1915 amperes (A).

Record the length of the line shown in millimeters.

Choose one will mark the Brainliest.

34.3

3.43

3.40

3.4

Answers

Boss, your ruler is in centimeters which means it’s roughly 34 mm

This line is measured on a cm scale and we need to convert to mm. To do that multiply the cm by 10.
When I look at the line the length is approximately 3.4 cm multiply that by 10 to get roughly 34 mm which matches with a

The two balls are an "action-reaction" pair. Ball 2 had a reaction to the action of ball 1, but ball 1 also had a reaction to ball 2. Explain how each ball moved after the collision in terms of the forces the balls exerted on each other.

Answers

Newton’s first law I guess

How much time does it take to use 300 W of power to do 1800 J of work? Round your answer to the nearest whole number. The time is s.

Answers

Energy = power × time
1800 = 300 × time
time = 1800 ÷ 300 = 6 s

Hope it helped!

Answer:

It takes 6 seconds

Explanation:

Power is the rate of doing work. Power used or dissipated can be calculated as the relationship between the work done and the time it took to do it. That's why its units are also J/s.

Mathematically:

[tex]Power=\frac{Work}{time}[/tex]

In this case, we know about the Power and the work done, so we can calculate the time it took. Solving for time:

[tex]time=\frac{Work}{Power}[/tex]

Plugging in the values:

[tex]time=\frac{1800J}{300J/s}\\time=6s[/tex]

PLEASE HELP ASAP :|

In a complete sentence using all keywords below, describe how you can charge a balloon and have it stick to the wall?

Keywords: wool/felt/hair,, balloon, electrons, wall, negative charge, and positive charge.

Make sure to use all keywords correctly for 6 points.

Answers

Rub a balloon on a woolen fabric to pick up some electrons, to make the balloon negatively charged, and stick them to a wall, which would be positively charged to make them stick.

Opposites attract and when you stick a negatively charged objects to positively charged objects, they tend to stick together. When you pick up electrons, it increases the number of electrons which will make the object negatively charged.

Note: The first part of the answer is a single sentence. The problem says in a complete sentence, so just in case that you need only one sentence you can take the first part. If you can add in more than a sentence, you can put in more from the second paragraph.

the combination of all forces acting on an object is called _____.

Answers

The answer is net force akaskakska

what is the spring constant of a bungee cord that stretches an additional 28m when 300 n of force are applied

Answers

The magnitude of the force applied to the spring is equal to (Hook's law)
[tex]F=kx[/tex]
where k is the constant of the spring and x is the displacement of the spring with respect to its relaxed position.
In the exercise, the force applied is F=300 N while the displacement is x=28 m. Therefore the spring's constant is
[tex]k= \frac{F}{x}= \frac{300 N}{28 m}=10.7 N/m [/tex]

English help please
The last answer says archer

Answers

it's the letter A it demonstrates...

it is the first answer
hope this helps!!!

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Simplify: 4x + 4y + 4z A) 4 + xyz B) 4x3y3z3 C) 4xyz D) 4x + 4y + 4z A credit card advertises an annual interest rate of 23%.What is the equivalent monthly interest rate?i=__^_t Which of the following body parts has smooth muscles? Biceps Heart Triceps Stomach a number multiplied by -8, subtracted from the sum of 14 and five times the number 13 is 20% of what number Before the industrial revolution, the most important source of fuel was Why was the defeat at the Alamo in 1836 significant for Texas? The nurse is assessing a 65-year-old patient with a history of smoking. The patient reports a frequent, productive cough of thick, pale yellow mucous. The nurse notes cyanosis is present in the patient. Which condition is consistent with these findings? Judy built a rectangular patio that is 9 meters wide and has a perimeter of 40 meters what is the length of Judys patio A client who had surgery for a laryngectomy is returned to the surgical unit from the postanesthesia care unit. in which position is it most appropriate for the nurse to place the client at this time? The case of little albert is used by behaviorists to explain ____.a. obsessive-compulsive disorderb. generalized anxiety disorderc. posttraumatic stress disorderd. phobias which country defeated the Arabs in the battle of tours 1. decide which of the following day to day activities might be considered aerobic exercise ? ( 1point ) A . surfing the web b. taking a catnap c. mowing the lawn d. paying bills Which solid has six faces, four lateral faces, two bases, eight vertices, and 12 edges? square pyramid triangular prism rectangular prism triangular pyramid Josie has $80. Addie has $60. In how many months will they both have the same amount of money if Josie saves $30 per month and Addie saves $40? What attracted many african americans to the north and midwest? Yo fui al cine anoche. Mi ___________ favorito era Juan Marcos porque es muy guapo y es muy bueno. No me gustaban las actrices. No eran buenas Which describes simple, solid instruments that produce sound by struck, scraped, or shaken?A. Aerophones B. Chordophones C. Idiophones D. Membranophones Use the following article to answer the question: The modern Tea Party emerged in 2009 as a response to the Emergency Economic Stabilization Act of 2008 and the American Recovery and Reinvestment Act of 2009. These two bills represented the government's response to the economic hardships facing Americans in 2009. But Tea Party members felt that the bills were wasteful and added too much to the national debt. According to one supporter, "this tea party movement is a message to Washington that we're unhappy and that we want things done differently." Tea Party opponents argue that its members are overly conservative and ill informed. When asked about the Tea Party, Senior White House Advisor David Axelrod said, "The thing that bewilders me is this President just cut taxes for ninety five percent of the American people. So I think the [Tea Party] should be directed elsewhere, because he certainly understands the burden that people face." The Modern Tea Party gets its name from the Boston Tea Party that took place in Boston Harbor in 1773 the Boston Tea Party that took place in Boston Harbor in 1873 the relationship between the U.S. and Britain nurtured by tea parties the arguments between the U.S. and Britian over tea parties in the New World The sandbox at the playground is 2 feet tall. The area of the base of the sandbox is 80 square feet