Swimming is the self-propulsion of a person through water, or a liquid substance, usually for recreation, sport, exercise, or survival. Locomotion is achieved through coordinated movement of the limbs and the body. Humans can hold their breath underwater and undertake rudimentary locomotive swimming within weeks of birth, as a survival response.Swimming is consistently among the top public recreational activities, and in some countries, swimming lessons are a compulsory part of the educational curriculum. As a formalized sport, swimming features in a range of local, national, and international competitions, including every modern Summer Olympics.
Swimming pool test kits combine a few drops of an unknown chemical with about 10 mL of pool water and then check the color of the reaction.
I would like to know the chemistry behind this. I assume that the H+ and/or the OH- ions combine with some cheemical to produce the color to be checked...
The Exodus thread got me thinking about swimming pools in a rotating space station.
Assume two scenarios: two toroidal pools that circumscribe the station, one is continuous and one is divided into segments by barriers.
(Sorry, typing on my phone is very arduous for these old thumbs, so I...
Problem statement : While the statement is given above, I draw the given image for the problem.
Attempt : It is clear at the outset that, since the velocity of river is constant, the man will not take the same time for the forward and reverse journeys. For both journeys however, the Relevant...
It is killing me trying to understand why sodium ions don't continuously build up in swimming pools.
You add NaCl to a pool. It is electrolysed to H2 and Cl2 leaving Na+ and OH-.
I get OH- builds up over time, and needs to be neutralised by HCl to make NaCl again and water. This would balance...
The first sketch is what I assumed would happen, where the light beams bends. And the second is meant to depict the light forming a cone, which I don't understand.
[Mentors provided help re-posting the image that was missing]
Hello,
I'm trying to create a simulation of swimming "Animats" (artificial animal). However, I'm only an high school student, so I don't know how to deal with fluid drag and fluid dynamics.
In this link you could find a short animation I made describing the swim motion my animat is going to...
What's up guys. Is there anyone who can challenge to solve this theoretical problem that can help to solve my house problem?
There's an empty outdoor swimming pool that has width a, length b, and depth c, such as its volume = abc. The temperature of outside is -3 C° and we are trying to fill...
Hi, I have a homework and I am not sure about some things.
1. Homework Statement
Person A and person B are next to river. Velocity of river is 1 m/s. There is a person drowning 30 m from shore. He doesn´t move, because there is a something, which he can hold. People A and B are 40 far from...
Is due to a collision between the head of the 20-man wall at the swimming pool can crack the back of the pool as in the following picture?
Professional anyone who knows the man's skull and pool tiles?
I just swam back and crashed against the pool with his head, and since I'm in pain and cervical...
Homework Statement
Some underwater fish use a jet to move forward. The body expands with water and contracts, expelling water and thus propelling forward. For these purposes, assume that a submerged fish experiences a friction drag proportional to its surface area ##A_s## and proportional to...
if the person sitting in the boat throws a pebble to the swimming pool. Pebble was initially contained inside the boat and of course it has higher density than water.
Homework Statement
A boy and a girl both swim at 3.0m/s. They jump into a river 1.0km wide, with a current of 2.0m/s[E].
a.) The girl swims so that she ends up directly across from her starting point. What is her velocity relative to the ground?
Homework Equations
Note: V = velocity with...
I need to work out the most cost effective way to maintain a swimming pool in a UK holiday complex that is closing for 1 month in January and hope that someone can help.
I would like to know if it would be cheaper to turn off the heating system for a month and then reheat it from base...
Hello,
Let's say I have an ideal cylindrical pool (rigid, vertical walls) of diameter d, with water of depth h. Take the ratio of d:h to be around 5:1 - 10:1. If I press down on the surface with a plunger of width w, I cause a standing wave resembling a single-node Bessel function, like a...
What will happen to a 110 pound man jumping from 80 feet into water feet first? I have done the math he hits the water at around 50 mph. How will this damage his body?
Homework Statement
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A swimmer located at point A needs to reach a point B 20 meters downstream on the opposite bank of a 10 meter wide river. The river flows horizontally at a rate of 0.5 meters/second, and the swimmer has a constant speed of 0.25 meters/second.
Set up the vector...
Hey! :o
Suppose that a duck swims in a circle $x=\cos t$, $y=\sin t$ and that the temperature of the water is given from the formula $T=x^2e^y-xy^3$. Find $\frac{dT}{dt}$:
using the chain rule
expressing $T$ as a function of $t$ and differentiating
At the chain rule do we not have...
Homework Statement
A swimming pool has dimensions 25 m x 10 m x 3m (length x width x height.) When it is filled with water, what is the force on the bottom (Fb) of the pool? On the long side (Fl)? On the short sides (Fw)? (note that integrals are required.) If you are concerned with whether or...
Homework Statement
If you were trying to swim across a river with the shortest possible time, would you aim your body slightly upstream, directly across the river, or slightly downstream? Explain.
Homework Equations
no equation needed
The Attempt at a Solution
i feel the answer is downstream...
Homework Statement
A river is 400 feet wide and flows at 1 ft/s. A swimmer swims at 2 ft/second, straight across the river and back to where he started on the original shore. Find the time required to complete his trip.
To clarify, the turn around point is straight across the river.
(I have...
During summer my swimming pool is 23° C and my loft air is 53° C. (73° F / 127° F)
The sun shines on the metal roof with 1x10^5 to 1x10^6 W and I hope to move 10.000 - 20.000 W to the pool.
To move the heat down by an external water circuit to the water/water heat exchanger by the pool...
Let's say we have two rooms in a mansion that have the same temperature. One of these rooms contains an indoor swimming pool. If the temperature outside cools down, will the room with the swimming pool "steam up"? Or will it rather be the other room without pool that does that?
I'm thinking the...
Homework Statement
A man can swim through still water 4.2m/s. Suppose this man swims in a river with current 1.3 m/s. Find his average speed over a trip:
a) across the river and back
b) a certain distance downstream and back
The Attempt at a Solution
a)
Here is a diagram I made:
Left side of...
Homework Statement
A person swimming 0.95 m below the surface of the water in a swimming pool looks at the diving board that is directly overhead and sees the image of the board that is formed by refraction at the surface of the water. This image is a height of 6.00 m above the swimmer. What...
Optics question -- coin at the bottom of a swimming pool
The apparent depth of a pool depends on the angle of viewing. Suppose that you place a coin at the bottom of a swimming pool filled with water (n = 1.33) to a depth of 2.16m.
Find the apparent depth of the coin below the surface when...
A swimming pool is 20 ft wide and 40 ft long and its bottom is an inclined plane, the shallow end having a depth of 3 ft and the deep end, 9 ft. If the pool is full of water, estimate the force on one of the sides.
They mean one of the trapezoidal sides, not the rectangular ones. Anyway, I've...
Homework Statement
You and a friend are at opposite sides of a large swimming pool, 20.0 m apart each holding onto a large inflated ball. You decide to launch water waves at each other by moving the balls downward into the water and back up at a tae of one cycle per second. You both push the...
This question has me puzzled, I only have a little bit of a clue of how to do this. Any and all help is greatly appreciated:)
Homework Statement
Chinook salmon are able to move through water especially fast by jumping out of the water periodically. This behavior is called porpoising. Suppose...
Ok, so I know why your arms move you forward in swimming. You are pulling the water back which pushes you forward a lot because there is a lot of resistance, and then you are moving your arm forward in the air which offers little resistance to push you back. So the amount you push back in the...
A spring is mounted vertically at the bottom of an empty swimming pool. A block of mass M = 857 kg is attached to the spring, and it compresses the spring from its equilibrium position by distance xo. Now the swimming pool is filled with fresh water, and the block is submerged. You find the the...
Homework Statement
A girl with mass m kg steps into her inflatable ring with horizontal cross sectional area Am^2 and jumps into the pool. After the first splash, what is the frequency of the girl bobbing up and down?
Homework Equations
I assume that we need the extra force,F_e, after...
Homework Statement
A lifeguard who can swim at 1.2 m/s in still water wants to reach a dock positioned perpendicularly directly across a 550 m wide river.
a. If the current in the river is 0.80 m/s, how long will it take the lifeguard to reach the dock?
b.If instead she had decided...
Hey guys,
I recently noticed that, after a swim, when you look at the light, you see a spectrum around it. The light was white light. And you see it with naked eyes.
Can you guys explain this phenomenon?
The water did contain Chlorine and maybe other necessary chemicals required in...
The energy required by a fish swimming at speed v to travel a distance L>0 in a current of speed u>0 is given by
E(v) = aL((v^3)/(v-u)), v>u
where a>0 is a proportionality constant.
a) Find the speed of the fish which results in minimal energy expenditure.
b) Give a qualitative sketch of...
Homework Statement
The human lungs can function satisfactorily up to a limit where the pressure difference between the outside and inside of the lungs is 1/21 of an atmosphere. If a diver uses a snorkel for breathing, how far below the water can she swim? Assume the diver is in salt water whose...
A swimming pool in the village of Røyken is getting a rather sinister reputation:
In two yeats, it has managed to entrap two horses, that had to be lifted out with a crane.
The images are from the two rescue operations...
How could sodium chloride produce chlorine (neutral atoms rather than ions) in a swimming pool?
I have always understood that chlorine takes an electron from sodium, because it's nucleus can pull more strongly on it. So, if the two were broken apart, wouldn't the chlorine keep the electron...
Homework Statement
A swimming pool is circular with a 40-ft. diameter. The depth is constant along east-west lines and increases linearly from 2 ft.at the south end to 7 ft. at the north end. Find the volume of water in the pool.
Homework Equations
Dont know how to enter integrals...
I am interested in understanding and being able to calulate the rate of evaporation and the volume lose over time of the salt water.
Surface area is 190 sf
Depth 4'
average air temp 75 deg. F
Daylight hours 12
Average wind speed 5 mph
Humidity 65%
Homework Statement
A swimming pool with 95000L of water with a pH of 8.9 needs to be lowered to a more suitable pH using an acidic substance. An ideal pH would be within the range of 7.2-7.6, so let's just assume that the pH we're hoping to achieve is 7.4. My brother chose...
Hello,
I feel a little out of place here, as I have no physics background whatsoever, but I was hoping you folks here might be able to help settle a debate. My brother and I like to have "what if" discussions, and one we had quite awhile ago was whether a person could walk across a swimming...
On Swimming Pool Levels...
Alright, this should be a simple enough question.
Per code, the pipe which feeds my swimming pools self-leveling pump has a valve to prevent back flow, so swimming pool water does not contaminate the residential main. However, the valve is located at a point...
Homework Statement
The water in a river flows uniformly at a constant speed of 2.50m/s between two parallel banks 80.0m apart. You are to deliver a package directly across the river, but you can only swim at 1.5m/s.
If you choose to minimize the distance downstream that the water carries...
Homework Statement
A swimmer is standing on the west bank of a river 600 m wide. The current in the river is 3.0m/s and the swimmer can swim 5.0 m/s in still water.
a) If the swimmer swims due east, what is the time it takes to get across the river?
b) What is the minimum time to get across...
Homework Statement
A swimming pool has dimensions 30.0 m and 10.0 m and a flat bottom. When the pool is filled to a depth of 2.00 m with fresh water, what is the force caused by the water on the bottom? On each end? On each side?
Homework Equations
B = pgV
P1+pgh+1/2pv2
The Attempt...
I have a question which relates to buoyancy and swimming.
One of the basic skills required to be a good swimmer is to be able to maintain a horizontal postion throughout the length of your body whilst swimming front crawl but to rotate your whole body about a horizontal axis which passes...