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WSU Physics Videos
United States
Registrace 5. 03. 2018
The primary idea of the project "Demonstrations in Physics" is to create videos of physics demonstrations recorded in a classroom environment comparable to actual lecture presentations made to students in physics courses. These movies have been designed so that they can be used by physics faculty at any institution. The videos can be used by faculty to supplement their own lectures and demonstrations through the showing of all or parts of these movies to the students. Also, the movies have been produced with the goal in mind that faculty could watch them and then reconstruct their own live demonstrations. The required equipment and supplies, in most cases, would likely be available in their own respective departments.
amazing demonstrations, explains air column resonance theory very well
Wow, fascinating😊
Not all expanding gas hits a wall. All these explanations basically say that gas gets cool when it expands, because of expansion cooling.
ভাষা বুজি না
unconvincing
This man explains like first grade student, very complicated. This is why you are not getting better, than worst. They kill your brain, with single ammo, the BIGGEST LIE. Learn physics by experience it yourself, do not learn from THE-MAN-MADE-UNIVERSITY.
straight fire
nice.
This explanation is incorrect. . If you don't know what entrainment is, please look it up. It does have to do with viscosity. . Look closely at the zoom-in at time 1:05. . A drawing would help. . The Inside diameter {ID} of the nozzle is smaller than the hose ID. This leaves a blunt edge of that nozzle rim where the smaller stream of water exits into the wider hose. . There will be water right up against that blunt rim forming a "stationary" water ring around the exiting jet of water. . The exiting jet will entrain that ring of water, drawing it downward along with the jet. Think of it as friction, or a viscosity effect. The blunt rim PREVENTS more water from filling-in to the space immediately below the rim. . Because that water ring is drawn away from the blunt edge, that lowers the pressure in that 'ring'. . With low enough pressure it can vaporize the water as he correctly says, causing tiny bubbles of water vapor to form that gives it that cloudy look as there is much turbulence within that ring of what is now tiny bubbles. . So it is NOT simply the low pressure "created by high velocity". That is sadly an all too common misunderstanding of Bernoulli that I call "Bad Bernoulli". . The high speed jet AND this BLUNT EDGE geometry is a set of constraints that together, with entrainment, are the causes of the lowered pressure. . It takes ALL of that, NOT JUST SPEED.!.!.! . When he turns up the flow you can see the soft hose being drawn in more, as well. . WHEN the hose is not pushed on, that jet of water will draw AIR along with it on the outside of the jet. Entrainment works between fluid types. . This is the 'shower curtain effect'; it is why a shower draws the curtain inward - - water entraining the air around it. it IS the entrainment removing the fluid around the jet and you have some surface preventing the fluid from flowing back into that space to replace that sir, THEREFORE causing a lowered pressure. . It takes ALL of those constraints for this to happen. . The water jet OUT OF the nozzle would be AT ATMOSPHERIC PRSSURE if there was no hose and other surfaces preventing a free flow of air around the jet. . . The air would easily flow in from along the 'bumpy' outside of the nozzle and follow the jet away from the nozzle - with the SAME kind of turbulence we see with an ordinary jet out in the open with turbulence around the ever widening jet. . He is ABSOLUTELY INCORRECT at 1:46 when he says: "So, once again when we have a high velocity, we have a low pressure." <--WRONG!. . It takes all of these constraints {or boundary conditions} for this pressure reduction to happen. . Bernoulli happens going from the elevated pressure NSIDE any blower to the lower atmospheric pressure outside the blower that we see the combination of the speed increase along with the pressure decrease as we move ALONG the flow. . The pressure within the jet decreases TO atmospheric pressure NOT below it.!. . . If that nozzle had a knife edge opening such that the ID of the nozzle and hose were identical, this would NOT happen.
Such a great teacher did not get any recognition
Thank you
But why is angular momentum conserved when when mg provides external torque ?
I myself came to the same conclusion while I was struggling with the concept! Beautiful!!!!❤
thank you
Very cool video. This explained exactly what I was curious about- if the speed/hardness of impact on a tuning fork could cause different harmonics.
really good
the charge resides in the field between the plates. the field energy IS the charge. current is transformed into the field between the plates. there are 2 types of current that can charge the capacitors field. one of them is the magnetic conduction current which flows from negative to positive. but there also is another current flowing from positive to negative and it is non magnetic. this current can be understood as a displacement current. these two currents that flow in opposite direction, when combined together create electric power.
Love this.
This hologram was on display at Mississippi State's physics department for a time. It's actually called a multiplex hologram, because it's a series of holograms of individual frames of motion picture film which were shot of a live person, as the camera moved around them, or they were on a turntable. This type of hologram technique was also seen in the movie, Logan's Run, and were produced by American Banknote. Thanks for sharing.
When the cat is held upside down, it tries to twist so you have to apply a balancing torque from each hand. When the cat is released, one hand is unconsciously released slightly before the other so for a brief moment a net torque acts resulting in a change in angular momentum so the cat rotates as a whole. If you concentrate on releasing both hands simultaneously, it doesn't flip.
Amazing sir ... 😊❤ Keep uploading more such videos
Bravo......hey watch ur video.....when u use tune fork it and talk it amplified ur voice......cheers
wonderful lecture sir
Except instruments like saxaphones and clarinets are closed pipes. The reed and mouthpiece are just the sound generating mechanism in the closed part of the pipe. Open pipe instruments are things like flutes and whistles. I'm just starting the hobby of making Irish whistles. Undergrad joke for this class... What instrument has a pipe that is closed on both ends? A drum.
This is incorrect because Bernoulli has to do with speed CHANGES, not simply speed. I say that this is misinterpreted. . There does appear to be something like cavitation where that cloudy area is, although you don't use that term, but I know that water will contain some dissolved nitrogen and oxygen (air). .. Also, it is not clear what you mean when you say that it "shuts itself off" as you turn the flow up. I still see a bit longer cloudy area. . . That said: . Bernoulli normally "happens" because there is a higher pressure INSIDE the faucet compared to atmospheric pressure outside it. The static pressure of the stream exiting the faucet into the atmosphere is AT atmospheric pressure. This is a Pressure Gradient that is the cause of the acceleration of water out the nozzle. A Pressure Gradient provides the force to Accelerate the water. Air out of your mouth or a blower / hair dryer is _AT_ atmospheric pressure - NOT below it. . If this is claiming that the fast stream of water out of the faucet has a pressure lower than atmospheric pressure ONLY because of ir "fast" speed, that is false. As I say, it is _AT_ atmospheric pressure and can be easily measured as such if you know how. . Adding the tubing complicates things making this a poor choice of a proof. . The added hose complicates the constraints because of the additional restriction of the tube walls. The stream will certainly entrain the surrounding water. This is a viscosity effect. Sorry. . Based on that, Watching closely, I think this is a result of entrainment. This is the same reason you can blow into those long "Bernoulli bags" with one breath. Entrainment, due to viscosity, draws more air in around the blown stream. .. If you think that stream out of the faucet, without the extra tubing, is below atmospheric pressure due to the fast speed, you are wrong. That is an all too common misconception about Bernoulli's Principle.
Yes, it also strikes me as somewhat a poor explanation for the observed phenomena. The flow of water at that speed is, more than likely, not laminar. The flow of water at the end of the nozzle is certainly not laminar and hence, Bernoulli's principle should not be applied here. I think the small stream of water out of the nozzle maintains its diameter for a while due to viscosity. Hence, this small stream impacts against the walls of the plastic hose until water can fill the entire diameter of the hose again. In the little space after the exiting of the nozzle, there must be empty spaces created by the small stream of water and evaporation might occur here, but it was not caused by the effects described by Bernoulli's equation, but due to effects associated with turbulent flow and viscosity.
@@ozkroca9003 PLEASE let me know with a reply, if you follow this. You are close. I now see what is happening. . If you don't know what entrainment is, please look it up. It does have to do with viscosity. . Look closely at the zoom-in at time 1:05. . A drawing would help. . The Inside diameter {ID} of the nozzle is smaller than the hose ID. This leaves a blunt edge of that nozzle rim where the smaller stream of water exits into the wider hose. . There will be water right up against that blunt rim forming a "stationary" water ring around the exiting jet of water. . The exiting jet will entrain that ring of water, drawing it downward along with the jet. Think of it as friction, or a viscosity effect. The blunt rim PREVENTS more water from filling-in to the space immediately below the rim. . Because that water ring is drawn away from the blunt edge, that lowers the pressure in that 'ring'. . With low enough pressure it can vaporize the water as he correctly says, causing tiny bubbles of water vapor to form that gives it that cloudy look as there is much turbulence within that ring of what is now tiny bubbles. . So it is NOT simply the low pressure "created by high velocity". That is sadly an all too common misunderstanding of Bernoulli that I call "Bad Bernoulli". . The high speed jet AND this BLUNT EDGE geometry is a set of constraints that together, with entrainment, are the causes of the lowered pressure. . It takes ALL of that, NOT JUST SPEED.!.!.! . When he turns up the flow you can see the soft hose being drawn in more, as well. . WHEN the hose is not pushed on, that jet of water will draw AIR along with it on the outside of the jet. Entrainment works between fluid types. . This is the 'shower curtain effect'; it is why a shower draws the curtain inward - - water entraining the air around it. it IS the entrainment removing the fluid around the jet and you have some surface preventing the fluid from flowing back into that space to replace that sir, THEREFORE causing a lowered pressure. . It takes ALL of those constraints for this to happen. . The water jet OUT OF the nozzle would be AT ATMOSPHERIC PRSSURE if there was no hose and other surfaces preventing a free flow of air around the jet. . . The air would easily flow in from along the 'bumpy' outside of the nozzle and follow the jet away from the nozzle - with the SAME kind of turbulence we see with an ordinary jet out in the open with turbulence around the ever widening jet. . He is ABSOLUTELY INCORRECT at 1:46 when he says: "So, once again when we have a high velocity, we have a low pressure." <--WRONG!. . It takes all of these constraints {or boundary conditions} for this pressure reduction to happen. . Bernoulli happens going from the elevated pressure NSIDE any blower to the lower atmospheric pressure outside the blower that we see the combination of the speed increase along with the pressure decrease as we move ALONG the flow. . The pressure within the jet decreases TO atmospheric pressure NOT below it.!. . . If that nozzle had a knife edge opening such that the ID of the nozzle and hose were identical, this would NOT happen. . PLEASE REPLY if you follow this. I am 100.00% certain this is the true physics. . Regards.
@@ozkroca9003 P.S. I also reviewed his other videos and I see he has several others on Bernoulli and repeats common demos and associated misconceptions, so he does not understand the physics, sorry. It is so frustrating.
best lecture Professor,i love the teaching aids
thank you for puting the efforts, very well done
Your first experiment (suspended ball in inverted funnel) demonstrates Bernoulli's principle well: the flow diameter increases, so the flow speed decreases, so pressure must have increased, so the ball is pulled upward toward low pressure. However, your second experiment does not demonstrate Bernoulli's principle, which describes the relationship between pressure and velocity *within a flow*. The principle says nothing about the difference in pressure between air inside and outside of a flow. Here are some ways you can see that the flow pressure is not lower than atmospheric pressure, as you claimed: 1. Note that the air flows out of the hose into the atmosphere, which can only happen if the air in the hose is at higher pressure. 2. Attach strings to the end of the hose and point the hose straight down; note that the strings are not moved horizontally into the flow. 3. Color the flow with dye and note that the flow doesn't get narrower as it would if it has lower pressure than the atmosphere. The reason for the ball being suspended in your tilted upward flow from the hose is that the upper, flow-side curved surface of the ball deflects some of the air molecules away from the flow due to that part of the flow sticking to and following the ball's surface away from the flow. By Newton's third law, this deflection of air away from the flow pulls the ball toward the flow. This is the Coanda effect.
First experiment is also Coanda effect. Whenever you have a jet of fluid flowing into a stationary fluid entrainment is gonna occur, so Bernoulli and the continuity equation cannot be applied here. As the jet moves around the ball , static air under the ball gets entrained in the jet , creating a low pressure region until that jet hugs the convex underside of the ball due to a vacuum been created. The removal of air from that region causes atmospheric pressure to hold the ball up. The purpose of the funnel is to create the pressure gradient that holds the ball up. The funnel prevents the atmospheric pressure from above from countering the atmospheric pressure from below that holds the ball up.
This is proper teaching <3
Thanks teacher the best explanation i ever found
Thought it was a video from one of my alamada and as an ex-Mechanical Engineer with a minor in heat and fluids I have an interest in Stirling engines which if energy is applied as an input produce significant cooling. Instead you gave a simple principle and an experiment of why this works. Most students don't realize how well this principle works as an energy input into a Stirling engine to produce cooling is the basis for cyro-genic cooling systems. ( Liguid oxygen, nitrogen, & etc manufacturing) Of course the theory revolves around Boyls ( probably misspelled it ) law.
Thank you sir!
waooo..best
Faraday was a Brilliant Person in his Times.....👍
what a fantastic demo.
Nice
❤
Great demo and explanation thank you❤
Shekesher
Vinny, chinni
In india class 5 student know about that
What material is it the Rope made of?
امير العبادي 5 دقايق من هذا فهمني اكثر من شرحك 8 اشهر رجعلي فلوسي
So good
👍🏻
👍🏻
Why circular patterns?
Why is he saying molecules ? Isn't it a beam of electrons ?
I am trying to solve the following. A sealed vessel contains a gas at P1=23.4PSI and temperature T1=300K. If a valve is opened so that in say 20 seconds the pressure drops to 15PSI. If the valve closes quickly, what is the gas temperature in the vessel? Does the Gay Lussac's Law apply giving T2=(P2/P1)*T1=210K?
This is helpful with martial arts too and the best move to describe this is the elbow to the face