A swimmer who can swim in still water at a speed of 4km/h is swimming in a river. the river flows at a speed of 3km/h. calculate the speed of the swimmer relative to the river bank when she swims:- 1. downstream 2.upstream​

Answers

Answer 1

Explanation:

Downstream: you just sum the magnitude of the velocity vectors:

3km/h + 4km/h = 7km/h

Upstream: difference of the magnitudes of the velocity vectors, in absolute value:

|3km/h - 4km/h| = 1km/h


Related Questions

Define faith in your own words.

Answers

Answer:

Faith, to me is almost like hope but for faith you need to believe. Some people associate the word faith with religion. But that's not it. Faith is really just a stronger term than believing someone. Like you can believe in someone but not have faith in that same person. You can have faith in someone but to do that you have to believe and trust them.

Explanation:

1. A roller coaster with a mass of 800 kg sits stationary at the top of a section of track, 75 m above

the ground as shown. When the brake is released, it starts to roll down the track


2. For each height represented in the diagram, calculate the gravitational potential energy using

Ep = mgh. Show ONE SAMPLE calculation in the calculations section below and fill in Table 1 for

each of the heights of the roller coaster. (6 marks)


3. Assuming there is no friction, determine the mechanical kinetic energy using Ek = Etotal - Ep.

Show ONE SAMPLE calculation in the calculations section below and fill in Table 1 for each of

the heights of the roller coaster. (6 marks)


4. For each height represented in the diagram, calculate the velocity using = �2

. Show ONE

SAMPLE calculation in the calculations section below and fill in Table 1 for each of the heights of

the roller coaster. (6 marks)


5. Use your answers to graph how gravitational potential energy, mechanical kinetic energy, and

velocity change as the roller coaster changes height. Use different colours for the three lines on

the graph. Graph paper is provided below. (3 marks)


6. Repeat steps 1 – 5 above for a roller coaster cart that has a mass of 300 kg and enter your

results in Table 2.

Calculations:

800 kg roller coaster cart:

Sample calculation for gravitational potential energy:

Sample calculation for Mechanical kinetic energy:

Sample calculation for velocity:


300 kg roller coaster cart:

Sample calculation for gravitational potential energy:

Sample calculation for mechanical kinetic energy:

Sample calculation for velocity:


Results:

Table 1: Potential energy, kinetic energy, total energy, and velocity of the 800 kg roller coaster cart


Table 2: Potential energy, kinetic energy, total energy, velocity of the 300 kg roller coaster cart.


Graphs:

It’s graphing time. These graphs are a bit different than the ones you did in the

data analysis assignment at the beginning of the course. In this case you have

three things to graph on each graph. (One graph for the 800 kg roller coaster cart

and one graph for the 300 kg roller coaster cart.) You need to graph the

gravitational potential energy with respect to height, the mechanical kinetic

energy vs height, and the velocity vs height.

Let’s look at the energy graphs first. In this case both kinetic energy and

mechanical energy cover the same range of values. This means they can use the

same scale on the y-axis. So, you will use the left y-axis and the x-axis to graph

the kinetic energy vs height and the potential energy vs height. You will need a

legend to explain which line is which. Colour coding is a nice way to highlight this.

The velocity values are much different than the energy values. This means you

need a totally different scale. So, your left y-axis won’t work. You need to make a

second scale on the right y-axis for your velocity values. You will plot the points

the same way as normal, but you will use the numbers on the right-hand scale

instead. Again, be sure to add your velocity line to the legend with a separate

colour code.


Discussion Questions:

1. Describe the relationship between the gravitational potential energy and the mechanical kinetic

energy of the roller coaster on your graph. (2 marks)

2. Describe the shapes of each of the three lines in the graph. Explain why the velocity is different.

(4 marks)

3. Describe how mass affects the speed at the bottom of the roller coaster. (2 marks)

4. Describe how mass affects the gravitational potential energy and the mechanical kinetic energy

of the roller coaster. (2 marks)

5. At what point does the roller coaster have a maximum value for the following? Justify your

answer by explaining why. (2 marks each)

a. Gravitational potential energy

b. Mechanical energy

c. Velocity

6. In your calculations, you assumed that the roller coaster was frictionless. All real roller coasters

encounter friction. Describe how the actual values of the variables would differ, or not differ,

from your calculated values for a real roller coaster. (Hint: what form of energy would some of

the total energy be converted to if there was friction in the system?) (4 marks)

How you will be graded:

Grades will be based on answering questions to demonstrate an understanding of the material covered

in this unit. Point form answers are okay if ideas are complete and use vocabulary (Word Bank)

provided. For questions out of 4 marks, there are 4 responses expected.

Answers

Answer:

Give me some hint please

Based on the calculations, potential energy of this roller coaster at a height of 75 meters is equal to 588,000 Joules.

How to calculate potential energy?

Mathematically, potential energy is calculated by using this formula:

P.E = mgh

Where:

P.E represents potential energy.m is the mass.h is the height.g is acceleration due to gravity.

Note: Acceleration due to gravity is equal to 9.8 m/s².

At a height of 75 m, we have:

P.E = 800 × 9.8 × 75

P.E = 588,000 Joules.

At a height of 60 m, we have:

P.E = 800 × 9.8 × 60

P.E = 470,400 Joules.

At a height of 45 m, we have:

P.E = 800 × 9.8 × 45

P.E = 352,800 Joules.

At a height of 30 m, we have:

P.E = 800 × 9.8 × 30

P.E = 235,200 Joules.

At a height of 15 m, we have:

P.E = 800 × 9.8 × 15

P.E = 117,600 Joules.

In conclusion, we can deduce that the potential energy of this roller coaster decreases with a decrease in height.

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4. Protons and neutrons are held together to form this _________

Answers

Answer:

strong nuclear force.

Explanation:

hope this helps you!!

One indicator NOT related to domestic violence is
violent attitudes
good nutrition
violations of court orders
substance abuse

Answers

Answer:

good nutrition

Explanation:

I think that one's pretty self explanatory

You are standing 30 m due east of a 50 kg person who is running at a speed of 20 m/s due west. What is the magnitude of that person's angular momentum about you (in units of )

Answers

Hi there!

We can use the following equation for angular momentum:

[tex]\large\boxed{L = mrv}[/tex]

m = mass (kg)

r = distance from reference point (m)

v = velocity (m/s)

We can simply plug-and-chug the values provided in the question.

L = (50)(30)(20) = 30000 kgm²/s

What is the weight of a 5kg object at the surface of the earth?

A. 49N
B. 49kg
C. 5.0kg
D. 25N

Answers

Answer: The answer is A) 49 N(Newtons).

I need help with this answer I believe it's a democracy​

Answers

Answer:

a. democracy

Explanation:

beacouse the government control of their members

A 4.0 kilogram projectile is fired horizontally from a 500 kilogram cannon initially at rest. The momentum of the projectile after being fired is 600 kilogram-meters per second to the north
(neglecting friction).
What is the speed of the cannon after firing?
0.83 m/s
1.2 m/s
o
3.3 m/s
150 m/s

Answers

The speed of the cannon after firing is 1.2 m/s

This can be solved using the law of conservation of momentum.

From the law of conservation of momentum,

⇒ The momentum of the projectile is equal to the momentum of the cannon.

MV = P................ Equation 1

⇒ Where :

M = mass of the cannon,V = velocity of the cannonP = momentum of the projectile.

⇒ make V the subject of the equation

V = P/M.................. Equation 2

From the question,

⇒ Given:

P = 600 kgm/sM = 500 kg

⇒ Substitute these values into equation 2

V = 600/500V = 1.2 m/s

Hence, The speed of the cannon after firing is 1.2 m/s

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A box of mass 7.7 - kg is accelerated from rest across a floor at a rate of 2.6 m/s2 for 18.5 s. Find the net work done on the box

Answers

Answer:

Explanation:

The net work will change the kinetic energy

W = ½mv² = ½m(at)² = ½ma²t²

W = ½(7.7)2.6²(18.5²) = 8907.3985 = 89 kJ

A woman skis from rest down a hill 20 m high. If friction is negligible, what is her speed at the bottom of the slope? Select one: O a. 20 m/s O b. 12 m/s O c. 400 m/s O d. 6 m/s​

Answers

Hi there!

We can use the work-energy theorem to solve.

Recall:

[tex]\large\boxed{E_i = E_f}}[/tex]

Initial energy = final energy

The initial energy is purely potential (she starts from rest), and, if we assign the bottom of the slope as the 0 line, her energy at the bottom is purely kinetic.

PE = mgh

KE = 1/2mv²

We can begin by setting the two equal:

mgh = 1/2mv²

Cancel out the mass and rearrange to solve for velocity:

2gh = v²

v = √2gh

Plug in given values and use g ≈ 10 m/s²:

v = √2(10)(20) = 20 m/s

The maximum speed with which an 1000 kg car makes a 180-degree turn is 10 m/s. The radius of the circle through which the car is turning is 24 m. Determine the force of friction and the coefficient of friction acting upon
the car.

Answers

109 is the answer There hope you do well

How many valence electrons do most stable atoms have?

A) one

B) two

C) four

D) eight

Answers

Answer:

D) 8

Explanation:

Due to the octet rule the most stable atoms will have 8 valence electrons.


9. P waves move faster than S waves A. True B. False

Answers

Answer: true
(I need 20 characters to submit the answer so I wrote this not to be confused with the answer)

Một chất điểm khối lượng m=200g chuyển
động chậm dần với vận tốc biến đổi theo qui luật
v=30 – 0,4t2 (SI). Lực hãm tác dụng vào chất điểm
lúc t = 5 giây là
A. 8 N B. 0,8 N C. 4 N D. 0,4 N

Answers

Can you please translate to English?

is xenon a pure substance​

Answers

[tex]\large\huge\green{\sf{Yes}}[/tex]


A 25.0kg boy is sliding on a frictionless frozen lake at 5.00m/s to the north when he is struck by a 1.00kg
snowball moving at 15.0m/s from the west. If the snowball sticks to him, how fast, and in what direction,
does the boy move after the collision?

Answers

The final velocity of the boy after the collision with snowball is 4.84 m/s at 18.4⁰ north-east

The given parameters;

Mass of the boy, m₁ = 25 kgSpeed of the boy, u₁ = 5 m/sMass of the snowball, m₂ = 1.0 kgSpeed of the snow ball, u₂ = 15 m/s

The initial momentum of the boy is calculated as follows;

[tex]P_y = m_1 u_1\\\\P_y = 25 \times 5\\\\P_y = 125 \ kgm/s \ \ north[/tex]

The initial momentum of the snowball is calculated as follows;

[tex]P_x = m_2 u_2\\\\P_x = 1 \times 15 \ \\\\P_x = 15 \ kgm/s \ \ west[/tex]

The resultant momentum of the boy and the snowball after collision is calculate as follows;

[tex]P_f = \sqrt{P_y^2 + P_x^2} \\\\P_f = \sqrt{125^2 + 15^2} \\\\P_f = 125 .9 \ kgm/s[/tex]

The final velocity of the system boy-snowball system is calculated as;

[tex]v_f(m_1 + m_2)= P_f\\\\v_f = \frac{P_f}{m_1 + m_2} \\\\v_f = \frac{125.9}{25 + 1} \\\\v_f = 4.84 \ m/s[/tex]

The direction of the boy after the collision is calculated as follows;

[tex]\theta = tan^{-1}(\frac{v_y}{v_x} )\\\\\theta = tan^{-1} (\frac{5}{15} )\\\\\theta = 18.4 \ ^0[/tex]

Thus, the final velocity of the boy after the collision with snowball is 4.84 m/s at 18.4⁰ north-east

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What are the characteristics of high energy wave?

A. Low frequencies and short wavelengths.

B. High frequencies and long wavelengths.

C. Low frequencies and long wavelengths.

D. High frequencies and short wavelengths

Answers

Answer:

D. High frequency and short wavelengths.

Explanation:

If a wave is high in energy it will have a higher frequency.

High frequency = short wavelengths

This is physics and it says collision and elastic/inelastic i need help

Answers

The initial velocity of the 3250 Kg mass is 2.1 m/s. The distance covered by the larger mass in 5s is 4.7 cm.

In this problem, we have to apply the law of conservation of linear momentum. Note that;

Momentum before collision = Momentum after collision

m1u1 + m2u2 = m1v1 + m2v2

(2150 × 10) + (3250u1) = (2150 + 3250)5.22

21500 + 3250u1 = 5400 × 5.22

3250u1  = 28188 - 21500

u1 = 28188 - 21500/3250

u1 = 2.1 m/s

2) Again from the principle of conservation of linear momentum;

(0.40 × 3.5) + (0.60 × 0) = (0.40  × 0.70) + (0.60 × v2)

1.4 = 0.28 + 0.60v2

1.4 - 0.28 =  0.60v2

v2 = 1.87 cm/s

Using;

s = 1/2 ( u + v)t

s = 1/2(0 + 1.87) × 5

s = 4.7 cm

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A textbook weighs 34 N on the surface of the Earth. What is the book’s mass on Earth’s surface?

Answers

Answer:

About 3.47kg

Explanation:

Recall that weight is equal to mass times acceleration.

In this case, our acceleration is due to gravity which on earth is about 9.8m/s/s

So we have 34N=9.8 *mass, divide both sides by 9.8 we get mass is equal to about 3.47kg.

A 2.40 kg ball is attached to an unknown spring and allowed to oscillate. The figure below shows a graph of the ball’s position �� as a function of time . What are the oscillation’s: a. period; b. frequency; c. angular frequency; d. amplitude; and e. What is the force constant of the spring?

Answers

(a) The period of the oscillation is 0.8 s.

(b) The frequency of the oscillation is 1.25 Hz.

(c) The angular frequency of the oscillation is 7.885 rad/s.

(d) The amplitude of the oscillation is 3 cm.

(e) The force constant of the spring is 148.1 N/m.

The given parameters:

Mass of the ball, m = 2.4 kg

From the given graph, we can determine the missing parameters.

The amplitude of the wave is the maximum displacement, A = 3 cm

The period of the oscillation is the time taken to make one complete cycle.

T = 0.8 s

The frequency of the oscillation is calculated as follows;

[tex]f = \frac{1}{T} \\\\f = \frac{1 }{0.8} \\\\f = 1.25 \ Hz[/tex]

The angular frequency of the oscillation is calculated as follows;

[tex]\omega = 2\pi f\\\\\omega = 2\pi \times 1.25\\\\\omega = 7.855 \ rad/s[/tex]

The force constant of the spring is calculated as follows;

[tex]\omega = \sqrt{\frac{k}{m} } \\\\\omega ^2 = \frac{k}{m} \\\\ k = \omega ^2 m\\\\k = (7.855)^2 \times 2.4\\\\k = 148.1 \ N/m[/tex]

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Determine the rTo understand the concept of nodes of a standing wave.
The nodes of a standing wave are points where the displacement of the wave is zero at all times. Nodes are important for matching boundary conditions, for example that the point at which a string is tied to a support has zero displacement at all times (i.e., the point of attachment does not move).
Consider a standing wave, where y represents the transverse displacement of a string that extends along the x direction. Here is a common mathematical form for such a wave:

y(x,t)=Acos(kx)sin(ωt),

where A is the maximum transverse displacement of the string (the amplitude of the wave), which is assumed to be nonzero, k is the wavenumber, ω is the angular frequency of the wave, and t is time.
Part A
Which one of the following statements about wave y(x,t) is correct?

adius of the 236U nucleus.

Answers

Answer:

The nodes of a standing wave are points where the displacement of the wave is zero at all times nodes are important for matching boundary conditions for example that the point at which a string is tied to a support has zero displacement at all times ie the point of attachment does not move consider a standing

when the tides are especially weak it is called a _____ tide

Answers

Answer:

When the tides are especially weak, it is called a NEAP tide.

Explanation:

Hope this helps :)

Answer:

Neap

Explanation:

Answered!

True or False. What makes faith genuine is its object.

Answers

Answer:true

Explanation:

Two forces act on a block as shown in the picture. What is the net force of the block?

30 N to the right

30 N to the left

10 N to the left 10

10 N to the right

Answers

Answer:

10 N to the left.

Explanation:

Since the forces are acting in opposite directions, you need to calculate the difference.

20 N - 10 N = 10 N

More force is being exerted to the left. Therefore, the net force is 10 N to the left.

f. Protons and neutrons
2. TRUE or FALSE: An object that is positively charged contains all protons and no electrons
3. TRUE or FALSE: An object that is negatively charged could contain only electrons with me
accompanying protons
4. TRUE or FALSE: An object that is electrically neutral contains only neutrons.

Answers

An object which has more electron than proton is negatively charged, otherwise positively charged. Every statement is false

What is atom?

Atom is the smallest unit of the matter consist of the positive charged nucleus and the electrons which moves around it. The atom can not be divided further.

The atom of a matter is made by three elements-

1) Neutron-Neutron is the element of atom, which has zero charge.2) Proton-Proton is the element of atom, which has positive charge.3) Electron-Electron is the element of atom, which has negative charge.

For the Protons and neutrons, lets check all the statement wheather they are true or false.

2. An object that is positively charged contains all protons and no electrons- An object which is positively charged, has more number of proton than electron. This is a false statement.3. An object that is negatively charged could contain only electrons with me accompanying protons- An object, which is negatively charged, has more number of electron than proton. This is a false statement.4. An object that is electrically neutral contains only neutrons-The number of electron and proton is equal in an electrically neutral object. This is a false statement.

Thus, every statement is false as a object which has more electron than proton is negatively charged, otherwise positively charged.

Learn more about the atom here;

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I need help with us history

Answers

Answer:

English is the language

Answer: im most likely wrong but i think its A

Explanation:


Two Blocks are connected by a massless rope over a massless,
frictionless pulley, as shown in the figure. The mass of block 2
is m2 = 10.1 kg, and the coefficient of kinetic friction
between block 2 and the incline is Mk = 0.200. The angle 0 of
the incline is 27.5º. If block 2 is moving up the incline at
constant speed, what is the mass mi of block 1?

Answers

The mass of block 1 will be 1.99 kg.The tension force is applied along the whole length of the wire, pulling energy equally on both ends.

What is tension force?

The tension force is described as the force transferred through a rope, string, or wire as it is pulled by opposing forces.

Given that,

Mass of block 1=? kg

The coefficient of the kinetic friction,μ=0.200

Now consider the weight component in the uphill direction.The weight is found as;

[tex]\rm W=m_1gsin \theta[/tex]

The force is balanced in the vertical direction as;

[tex]\rm T=F_f-W[/tex]

When the force of friction is;

[tex]\rm F_F=\mu_k N[/tex]

[tex]\rm F_f=(m_1 gcos \theta)[/tex]

Substitute the value in the vertical balanced equation;

[tex]\rm T=m_1gsin(27.5)^0-\mu_kmgcos27.5^0[/tex]

[tex]\rm T-m_2g=0\\\\T=m_2g[/tex]

[tex]\rm (10.1) g=m_1g(0.699-0.2 \times(-0.714) ) \\\\ (10.1) g=m_1g (0.699+0.1428) \\\\\ (10.1) g= m_1 \times 0.8418 \\\\ m_1 =11.99 \ kg[/tex]

Hence the mass of block 1 will be 1.99 kg.

To learn more about the tension force refer to the link;

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a
A person throws a ball up into the air, and the ball falls back towar
would the kinetic energy be the lowest? (1 point)
at a point before the ball hits the ground
when the ball leaves the person's hand
o when the ball is at its highest point
at a point when the ball is still rising

Answers

Answer:

when the ball is at its highest point

Explanation:

Provided the ball returns to where it was thrown. The velocity, and therefore kinetic energy, will be momentarily zero at the highest point of the throw.

What happens to the gravitational force between two objects if the distance between them triples?

A. The force increases by a factor of 9

B. The force decreases by a factor of 9

C. The force decreases by a factor of 3

D. The force increases by a factor of 3

Answers

So as two objects are separated from each other, the force of gravitational attraction between them also decreases. ... If the separation distance between any two objects is tripled (increased by a factor of 3), then the force of gravitational attraction is decreased by a factor of 9 (3 raised to the second power).

So the answer you are looking for is B.
The answer will be B.

Gravity obeys something called the inverse square law.

This means if distance increases by a factor of x, the force of gravity will decrease by a factor of x^2

For example, if distance increases by 2, the force would be 4 times weaker

If Distance increases by a factor of 3, the force will be 9 times weaker

Which statement is true for a series circuit

Answers

Answer: they have one path to flow

Explanation: share the same current

In a series circuit, the current is the same at each resistor. If the light bulbs are identical, then the resistance is the same for each resistor. The voltage drop (I•R) will be the same for each resistor since the current at and the resistance of each resistor is the same.
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When the teacher entered to class we -(finish /finished /had finished ) our work The heights of adult men in America are normally distributed, with a mean of 69.1 inches and standard deviation of 2.65 inches. It is sometimes said that women don't like to dance with shorter men. To get a dancing partner, a 6-foot two-inch tall woman draws from a hat the name of an adult American male. What is the probability that he will be as tall as she? Noah is making grilled cheese sandwiches for friends. He has 24 ounces of cheese. He plans to split thecheese evenly between 6 sandwiches.Write an equation to determine how many ounces of cheese, c, Noah can use on each sandwichHow many ounces of cheese can Noah use on each sandwich? What is the name of the tab that becomes available after you add and select an image in your PowerPoint presentation? Home Insert Picture View I need help please its for school Yellow bricks are used to build yellow houses. Blue bricks are used to build blue houses. Red bricks are used to build red houses. What kind of bricks are used to build greenhouses The length of a certain rectangular prism is 3 less than twice the width. The height of the same prism is 4 more thanthe width. Write an expression to represent the volume of the rectangular prism in terms of width (w).V=2w? + 5w-12V= -2w3 + 11w2 + 12wV=2w3 +5w? - 12w..DV=4w + 1 what are some examples of direct in the christmas carol write a paragraph about visit to the Art gallery by using present continuous tense Question 1: Four expressions are shown below:A. 2(4x + 2)B. 2(3x + 3)C. 6x + 6D. 8x + 4Which two expressions are equivalent to 2(3x + 2 + x)? (5 points)A and DB and DA and CC and BQuestion 2:Which of the values in the set {3, 4, 5, 6} is a solution to the equation 4x + 2 = 22?3456 Please Help Question in picture there are 64 female performers in a dance recital. the ratio of men to woman is 5:8 how many men are in the dance recital can u help me with this What is the opinion that is being conveyed by the cartoonist? Find the area in square feet of a rectangle with a base of 3 feet and a height of 4 1/3 feet. that had nothing to do with the question Realism + NaturalismWhat is time of this period?What happened? Who was in that period?If you and answer my question, i'll give you 5 stars and a heart.if you answer not correct and for score i'll report you.( You can search it, just because i'm lazy to read it. ) Use this dictionary entry to answer the question. capt. (core root) take; seize What does the word captivated mean as it is used in this sentence? The play captivated me; I felt transported to another place and time. a statement that is made by a captain unable to make someone understand kidnapped or taken against one's will held a person's attention completely what the sum of 9999x23 In one to two sentences, describe an experiment that would show that intramolecular forces (attractions between atoms within molecules) are stronger than intermolecular forces (attractions between molecules).(2 points)