[URGENT] A swimmer wants to end up at a dock due north of her starting position on the south shore of a river. In still water her maximum speed is 1.25m/s. The river has a current flowing 0.35m/s [E].
a.) calculate the direction that she must aim herself through the water to arrive at the dock.
b.) how long will it take for the swimmer to cross the river, if the distance from the starting point to the dock is 300 m?
Please show all your work, thanks
Answers
Explanation:
As you can see in the picture, we want the swimmer to go on a straight line, so the speed of the water must be equal to the speed of the swimmer along the x-axis. We also know the value of v, so we can calculate the of the cosine of the angle (alpha) between Vx and V. Thanks to the fundamental relation of gioniometry (cos^2(x) + sin^2(x) = 1) we can find the sine of alpha and calculate Vy. With Vy we can calculate the time that the swimmer will use for reaching the dock: s = Vy * t => t = s/(Vy).
I'll let you do all the calculations, you just have to plug in values.
![[URGENT] A Swimmer Wants To End Up At A Dock Due North Of Her Starting Position On The South Shore Of](https://brainimage.s3.us-east-005.backblazeb2.com/answers/attachments/EGlAS6mrI1kVB7EuI5ipKmttiRbzdvwr.jpeg)
a)The direction that she must aim herself through the water to arrive at the dock will be 73.7°.
b)The time it takes for the swimmer to cross the river will be 240 seconds.
What is speed?Speed is defined as the rate of change of the distance or the height attained. it is a time-based quantity. it is denoted by u for the initial speed while v for the final speed. its si unit is m/sec.
Given data;
The maximum speed of the swimmer In still water,v=1.25m/s.
Speed of river = 0.35m/s [E]
α is the direction that she must aim herself through the water to arrive at the dock.
t is the time it takes for the swimmer to cross the river
The distance from the starting point to the dock is,s = 300 m
If the swimmer were to swim straight, the water's speed along the x-axis would have to match that of the swimmer.
[tex]\rm v_w = v_x = 0.35 \ m/sec[/tex]
α is the angle between vx and v
The value of the
[tex]\rm cos \alpha = \frac{v_x}{v} \\\\ \alpha = cos ^{-1}(\frac{0.35}{1.25} )\\\\ \alpha = 73.7 ^0[/tex]
The time that the swimmer will use for reaching the dock;
s = V×t
t = s/(v)
t=300 m / 1.25 m/sec
t = 240 seconds
Hence, the direction that she must aim herself through the water to arrive at the dock. and it takes for the swimmer to cross the river will be 73.7° and 240 seconds respectively.
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Related Questions
0. Kedija walked 300m from A to B and returned back and walked 200m and then stopped at 'C', what
is her change in position from A to in the figure below
300m
200m
A
С
B
C/-500m
D 100m
B/ -100m
A Soom
Answers
Answer:
100
Explanation:
Displacement is the shortest line between the starting point and the ending point
so , the starting point is "A"
,the ending point is "C"
so "AC" = AB - CB = 300 - 200 = "100"
Calculate the resistance of a 1km length, 1mm diameter wire made from:
a) constantan (\rho = 4.9 × 10-7 Ωm)
b) copper (\rho = 1.7 × 10-8 Ωm)
c) State which material is better suited for being used to make resistors, and justify your answer.
d) With 1 amp of current flowing through each of the wires how much energy is converted to heat?
e) What potential difference would be needed to force a current of 1 amp through that length of each type of wire?
Answers
From the values of resistivity, the resistance of copper wire is 22 Ω.
Let us recall that;
R = ρl/A
ρ = resistivity
l = length of the wire
A = cross sectional area of the wire
For constantan;
R = 4.9 × 10^-7 × 1 × 10^3/[3.14 × ((1 × 10^-3)/2)^2]
R = 620 Ω
For copper;
R = 1.7 × 10-8 × 1 × 10^3/[3.14 × ((1 × 10^-3)/2)^2]
R = 22 Ω
The material that is best suitable to make resistors is constantan wire.
For constantan, the energy converted to heat is;
I^2 R = (1)^2 × 620 Ω = 620 W
For copper, the energy converted to heat is;
I^2R = (1)^2 × 22 Ω = 22Ω
The potential difference of constantan = IR = 1 × 620 Ω = 620 V
The potential difference of copper = = IR = 1 × 22Ω = 22 V
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Draw a nitrogen cycle and explain in short.
please help me
Answers
Answer: biogeochemical process
Explanation:
what is the energy (in j) of a photon required to excite an electron from n = 2 to n = 8 in a he⁺ ion? submit an answer to three signficant figures.
Answers
Answer:
Approximately [tex]5.11 \times 10^{-19}\; {\rm J}[/tex].
Explanation:
Since the result needs to be accurate to three significant figures, keep at least four significant figures in the calculations.
Look up the Rydberg constant for hydrogen: [tex]R_{\text{H}} \approx 1.0968\times 10^{7}\; {\rm m^{-1}[/tex].
Look up the speed of light in vacuum: [tex]c \approx 2.9979 \times 10^{8}\; {\rm m \cdot s^{-1}}[/tex].
Look up Planck's constant: [tex]h \approx 6.6261 \times 10^{-34}\; {\rm J \cdot s}[/tex].
Apply the Rydberg formula to find the wavelength [tex]\lambda[/tex] (in vacuum) of the photon in question:
[tex]\begin{aligned}\frac{1}{\lambda} &= R_{\text{H}} \, \left(\frac{1}{{n_{1}}^{2}} - \frac{1}{{n_{2}}^{2}}\right)\end{aligned}[/tex].
The frequency of that photon would be:
[tex]\begin{aligned}f &= \frac{c}{\lambda}\end{aligned}[/tex].
Combine this expression with the Rydberg formula to find the frequency of this photon:
[tex]\begin{aligned}f &= \frac{c}{\lambda} \\ &= c\, \left(\frac{1}{\lambda}\right) \\ &= c\, \left(R_{\text{H}}\, \left(\frac{1}{{n_{1}}^{2}} - \frac{1}{{n_{2}}^{2}}\right)\right) \\ &\approx (2.9979 \times 10^{8}\; {\rm m \cdot s^{-1}}) \\ &\quad \times (1.0968 \times 10^{7}\; {\rm m^{-1}}) \times \left(\frac{1}{2^{2}} - \frac{1}{8^{2}}\right)\\ &\approx 7.7065 \times 10^{14}\; {\rm s^{-1}} \end{aligned}[/tex].
Apply the Einstein-Planck equation to find the energy of this photon:
[tex]\begin{aligned}E &= h\, f \\ &\approx (6.6261 \times 10^{-34}\; {\rm J \cdot s}) \times (7.7065 \times 10^{14}\; {\rm s^{-1}) \\ &\approx 5.11 \times 10^{-19}\; {\rm J}\end{aligned}[/tex].
(Rounded to three significant figures.)
What is the main force that must be overcome in order to push an object along a horizontal surface. no silly answers
Answers
Answer:
Frictional force
Explanation:
The force that must be overcome in order to push an object along a horizontal surface is frictional force
If the force is more than frictional force the object moves
PLZ HELP ME FAST A relationship between two variables is called:
A.
observable
.B.
correlation
.C.
causation
D.
finite.
Answers
Answer:
B- Correlation
Explanation:
Answer:
correlation
Explanation:
What happens to all light bulbs in a series circuit when one burns out? How would the situation change when the lights are hooked up in parallel?
Answers
Elliot jumps up and down on a pogo stick. He weighs 600.N, and his pogo stick has a spring with spring constant 1100N/m. What is the height he will reach when he has gravitational potential energy 250J? m
Answers
From conservation of energy, the height he will reach when he has gravitational potential energy 250J is 0.42 meters approximately
The given weight of Elliot is 600 N
From conservation of energy, the total mechanical energy of Elliot must have been converted to elastic potential energy. Then, the elastic potential energy from the spring was later converted to maximum potential energy P.E of Elliot.
P.E = mgh
where mg = Weight = 600
To find the height Elliot will reach, substitute all necessary parameters into the equation above.
250 = 600h
Make h the subject of the formula
h = 250/600
h = 0.4167 meters
Therefore, the height he will reach when he has gravitational potential energy 250J is 0.42 meters approximately
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A textbook is sitting at rest on a desk. Compared to the magnitude of the force of the textbook on the desk, how
would you describe the magnitude of the force of the desk on the book?
o less
O zero
O more
O equal
Answers
what is the horse power of an electric motor which can do by 1250 joule of work in 5 seconds
Answers
250 Joules per second = 250 Watts ( 1J/s = 1 Watt per definition)
250 Watts output = 250/0.65 efficiency = 384 Watts input
1 Horsepower = 732 Watts
Motors 1 Horsepower and under are made in certain step sizes like
3/4 , 1/2 , 1/3, 1/4, 1/16 1/20 of a Horsepower.
3/4 Horsepower is 549 Watts
1/2 Horsepower is 366 Watts
so you need to 3/4 horsepower motor to achieve 1250 J of work in 5 seconds.
Line segment Q R , Line segment R S and Line segment S Q are midsegments of Î"WXY. Triangle R Q S is inside triangle X Y W. Point R is the midpoint of side X Y, point S is the midpoint of side Y W, and point Q is the midpoint of side X W. The length of Q R is 2. 93 centimeters, the length of R S is 2. 04 centimeters, and the length of Q S is 2. 28 centimeters. What is the perimeter of Î"WXY? 11. 57 cm 12. 22 cm 12. 46 cm 14. 50 cm.
Answers
The perimeter of ΔWXY is : ( D ) 14.5 cm
Calculating the perimeter of ΔWXY
QR = WY / 2
RS = XW / 2
QS = XY / 2
Given that : QR = 2.93 cm , RS = 2.04 cm, QS = 2.28 cm
Therefore
Perimeter of ΔWXY = ∑ WY + XW + XY
= 2SR + 2QS + 2QR
= 2(2.04) + 2(2.28) + 2(2.93)
= 14.5 cm
Hence we can conclude that the perimeter of ΔWXY = 14.5 cm
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Answer:
The name of the shape on the right is M prime N prime O prime P prime Q prime R prime S prime because it is the image of the shape on the left.
Explanation:
a plane mirror forms a virtual image why
Answers
In an inelastic collision:
I. only momentum is conserved
II. only kinetic energy is conserved
III. momentum and kinetic energy are both conserved.
IV. neither momentum nor kinetic energy are conserved.
Answers
Hi there!
I. Only momentum is conserved.
An inelastic collision means that there is a LOSS in the KINETIC ENERGY of the system.
However, momentum is ALWAYS conserved for every type of collision unless there is an external force acting on the system.
Hope this will help.
Before Collision:
2,000 kg 4 m/s 4,000kg 0 m/s
After collision: 2,000 kg + 4,000kg Vt = ?
I will give Brainliest to the first person. Please show work
Answers
Answer:
4/3 m/s
Explanation:
Assuming momentum is conserved, the sum of products of mass and speed before the collision is the same as after:
(2000 kg)(4 m/s) +(4000 kg)(0 m/s) = (2000 +4000 kg)(Vt)
Vt = (8000 kg·m/s)/(6000 kg) = 4/3 m/s
The speed of the combined objects after the collision is 4/3 m/s.
what's the mass of the star rasalas?
Answers
Answer: The Rasalas's solar mass is 1.50 times that of our star, the Sun. The Sun's Mass is 1,989,100,000,000,000,000,000 billion kg.
Explanation:
Answer:
The Rasalas's solar mass is 1.50 times that of our star, the Sun. The Sun's Mass is 1,989,100,000,000,000,000,000 billion kg. which to calculate using this website is too large. To give idea of size, the Sun is 99.86% the mass of the solar system.
Explanation:
Which are the most likely products for the following reaction? Zn + CuSO4 --> ?
Answers
Answer:
It's going to be a single displacement reaction
So we'll get ZnSO4 + Cu for the following reaction Zn + CuSO4
Equation:
Zn + CuSO4 ------> Cu + ZnSO4
A diffraction grating is 1.50 cm wide and contains 2000 lines. When used with light of a certain wavelength, a third-order maximum is formed at an angle of 20.0°. What is the wavelength (in nm)?
Answers
Answer:
because of the gravity of the earth
what is a joule in physics?
Answers
Explanation:
Joule is unit of work or energy in the International System of Units (SI)
[tex] \large \mathfrak {Formula}[/tex]
work (joules) = force (newtons) x distance (meters)
[tex] \large\mathfrak{Invented \: by} [/tex]
James Prescott Joule
the gravitational force acts on all objects in proportion to their mass. neglecting air resistance, why don’t heavy objects fall faster than light ones?
Answers
Answer:
Because in correspondence to the same distance from a mass, the gravitational acceleration is the same for all the bodies. It doesn't depend on the mass of the objects.
A wave has wavelength of 10 m and a speed of 340 m/s. What is the frequency of the wave?
I need the Formula,Known,Substitute & Solve Answer with Units
Answers
Answer:
This is the answer that I got.
Explanation:
Hope it is right.
Please HELP
6. A 3.4-kg bucket of water is attached to a 1.0-m rope. The bucket is swung in a circle at a speed
of 10.0-m/s.
a.
If the rope can only tolerate 400-N of force, what is the maximum speed the bucket can
experience before the rope snaps? {Hint: Let the centripetal force be 400-N and solve for the speed)
Answers
Answer:
Explanation:
hope this helps
The maximum speed of the bucket can experience before the rope snaps if A 3.4-kg bucket of water is attached to a 1.0-m rope. The bucket is swung in a circle at a speed of 10.0-m/s is 10.85 m / s.
What is force?Force is the influence of either pull or pushes in the body. Basically, gravitation forces, nuclear forces, and friction forces are the types of forces. For e.g. when the wall is hit by a hand then a force is exerted by the hand on the wall as well as the wall also exerts a force on the hand. There are different laws given to Newton to understand force.
Newton is a unit of force used by physicists that is part of the International System (SI). The force required to move a body weighing one kilogram one meter per second is known as a newton.
Given:
The mass of the bucket, m = 3.4 kg,
The length of the rope, r = 1 m,
The speed of the bucket, v = 10 m / s,
The force of the rope, F = 400 N,
Calculate the maximum speed by the formula given below,
[tex]F_c = mv^2 / r[/tex]
400 = 3.4 v² / 1
v² = 400 / 3.4
v² = 117.6
v = 10.85 m / s
Therefore, the maximum speed of the bucket can experience before the rope snaps if A 3.4-kg bucket of water is attached to a 1.0-m rope. The bucket is swung in a circle at a speed of 10.0-m/s is 10.85 m / s.
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I need it in the next hour or so!
A sports car with a mass of 650 kg is accelerating at +3 m/s2. The force of friction is 200 N, the forward force from the engine is 3100 N. What must the force of air resistance on the car be? - Show your work - Include a unit with your answer
Answers
The car is accelerating at 3 m/s² in the positive direction (to the right). By Newton's second law, the net force on the car in this direction is
∑ F = F[a] - F[f] - F[air] = ma
3100 N - 200 N - F[air] = (650 kg) (3 m/s²)
Solve for F[air] :
F[air] = 3100 N - 200 N - (650 kg) (3 m/s²)
F[air] = 3100 N - 200 N - 1950 N
F[air] = 950 N
The Doppler technique for planet detection has found Earth-like planets around nearby Sun-like stars. (True or False) ____________________
Answers
Answer: false
Explanation:
Two students are sitting on a see-saw. The length of the board is 2 meters with the
pivot point being in the very center. One student sitting on the end of the left side
has a mass of 34 kg. If the student sitting on the right has a mass of 42.5 kg, where
should she sit for the see-saw to be in equilibrium?
Answers
To solve the problem it is necessary to apply the concepts of Torque and equilibrium.
The Torque is defined as:
Where
F= Force
d = Distance
In this particular case, the force is caused by the weight of both children.
In turn, when there is equilibrium, the two torques must be equal therefore
Replacing with our values
Re-arrange to find
Therefore the distance that the second kid should sit to balance the see-saw is 1.8m from the pivot.
2. Think about an activity you may have learned that involves muscle memory. Consider when you first learned the activity, how easy or difficult it was the first time, and if you can do it now without thinking. What happened in your brain during practices that resulted in muscle memory for you?
Answers
Answer:
Muscle memory is found in many everyday activities that become automatic and improve with practice, such as riding bicycles, driving motor vehicles, playing ball sports, typing on keyboards, entering PINs, playing musical instruments, poker, martial arts, and dancing.
Explanation:
why does the earth get more energy from the sun than from all the other stars in the universe combined
Answers
Answer:
Explanation:
The sun is much closer than the other stars
During which time does Jamal have the greatest momentum?
Answers
Answer:
Momentum Packet Answer KEY - Science Online
YOU WILL SEE THE PDF
how long does it take a man to travel 6 km if his speed is 3km/h?
Answers
why did my answer get deleted??
oh yeah i put a link on there- oopsies.
I wont this time!
I got 30!
An instrument made of brass is an example of which of these?
solid–liquid solution
solid solution
liquid–liquid solution
gas–liquid solution
Answers
Answer:
a solid made of liquid solution
Explanation:
a trumpet for example has intrcuite valves , the only way to do this is by creating a liquid form of the metal to be able to create the solid formed instrument.
Answer:
a solid made of liquid solution
Explanation:
domne
A car takes off from rest takes of from rest and covers a distance of 80m on a straight road in 10s.Calculate the magnitude of its acceleration.
Answers
Answer:
The magnitude of its acceleration is 1.6 m/s^2.
Hope you could get an idea from here.
Doubt clarification - use comment section.