Classical Physics

hi a question: is -0.5 half as large as -1, or is -0.5 twice as large as -1 this came up on our physics test... since -0.5 > -1, meaning -0.5 that its larger than -1, so saying something that's half as large would imply that its smaller? which clearly isn't the case....

I have found related information but I have not found anywhere on the Internet where this question is directly addressed. A more dense body is falling in a less dense column of fluid. Does the pressure from fluid on the walls of the container decrease? ( My guess is "yes". As the body falls the fluid is displaced upwards and so the fluid moves. ) Thank you : ) [ Edit: I should have said " does the pressure from the fluid on the walls decrease when the body is falling as opposed to before the body falls and the fluid is static ? " ]

according to the theory of relativity nothing can move faster than light. so then why has a craft that moves a substantial fraction of the speed of light been so elusive (such as .05) or even .25)?

hello guys, i have tried to build an alternator which also doubles as a magnetic thrust bearing here is the rotor: the inner 6 magnets are all facing the same way, and the outer 6 magnets are all facing the opposite way, this creates a 'horseshoe' magnetic field in a zig-zag pattern around the circle of the rotor... the 'star' is made out of mild steel and is acting as the 'magnetic flux conductor' here is the base: similarly, the outer ring of magnets are oriented in the opposite direction from the inner magnets, and the large flat disc is also made of mild steel... this is actually supposed to act as 2 large concentric magnets instead of 2 rings o…

This is a formula for finding orbital clusters around each element I worked on about a year ago, but, I could not find anyone on the forum to confer with me the ideas presented by myself. This follows, after the liquids, when metals begin, it takes on a formula. If you ever played dungeons and dragons, the magician's spell advancement table will show you the amounts of orbitals per level or proton beyond first, of course. This means there is one s orbital, or 'level one spell' at firs level, then, two s orbitals or level one spells at second level, then, a third new type of orbital with those previous ones at level three or with the third metal. At the fourth me…

My Physics text in High School contained the following statement, as closely as I can recall it: "X-rays may be bent and diffracted by means similar to visible light". I asked our instructor, if x-rays pass freely through a glass prism, how can the text's statement be valid? He was a recent college grad., his academic background unknown. He kind of shrugged, and as he usually answered the "unanswerable" said, "Read the book!"

Today in the Speculations forum (http://www.sciencefo...-go-on-forever/) I heard for the first time about Reidar Finsrud's machine. It is not perpetual motion, let alone free energy, but a machine said to have 99% efficiency. After 3 days in operation, it lost only 1/25 of a second so it appears to be harvesting energy from somewhere to offset friction and air resistance. For more details, and a video, check out that post and http://peswiki.com/i...erpetuum_Mobile The machine has been known since 1996 so I assume it might be known to some members of this forum. Finsrud calls the prime mover a "free force." The mechanism comprises a wobbling ball race connected to …

I'm "creating" a creature (actually just drawing it, but I want it to be almost like a bluprint with some sound scientific principles). I want to have a flying creature with a special outside shell. The general structure is very odd and doesn't need to be explained but basically I want this creature to actually get some energy from the heat that's generated by the friction from air resistance. This was basically my idea: The surface of the "body and wings" would be made of a hard surface that's actually a series of regularly spaced loops (like the hard side of Velcro only loops instead of hooks), with a pore spaced in between each loop. As the creature dives throu…

I was just wondering if it was possible to actually create these so called Mag-Lev vehicles and have them behave the way they did in the movie. I know they have been working on monorails and even a magnetic propulsion device that has the capactiy to launch rockets, saving all that costly fuel, but never any cars with this design. Also, the guns used in the scene in the car assembly line, I never figured out if it shot sound blasts or just intensified blasts of air. Thoughts on this?

Guys, you have GOT to help me out here. Today, I went with my grandparents and my little cousin to Santa Cruz, California, where we passed through (and entered) the "Mystery Point" - a place where they claimed the laws of physics are different. Obviously, I was sure everything is an optical illusion, but it sounded like a nice detour and a great experience, so we stopped by and got in. I am still slightly confused. There is no doubt that optical illusions were part of what we experiences, but it is DEFINATELY wasn't all it was. The forces active in that point were clearly felt and visible, and I have GOT to figure out what the heck it is that happened there. I n…

Curiosity question. We keep a small fridge and the temp is kept quite cold. When I take a bottle of sparkling water out, it is clearly in liquid form. When I open it, within 5-20 seconds the better part of the bottle has turned into a frozen slush. I'm aware that pressure can affect freezing temperature, but opening the bottle should lower the pressure which should actually raise the freezing temperature. What is happening here? I'm stumped.

2 questions: 1) Is the pull force of a (Neodymium) magnet cube (3/8" in this case) with side to side magnetizing through thickness, larger between a mild steel cube, same size, and the magnet or an identical magnet? 2) Same magnet: Is the pull force larger, if it is attached to a large steel plate instead of a cube the same size as itself, and if "yes", by how much? Thanks to all, who answer to this question!!! S

Introduction Hello folks, I've recently started teaching myself physics and one of the ways I do this was through hands-on experiments. I am looking for feedback on these, really any kind, for example Notes on experiment setup What would you have done differently? Mistakes, things not considered or mentioned How would you follow up on this experiment? Note: if the math on this page does not render properly for you, it is also available as a notion site here https://flawless-door-cdd.notion.site/Pendulum-Experiment-144c27137da88054b4eff55713e23c4e?pvs=74 Goal Measure the relationship between a pendulum length and its per…

While we are told that g = 9.81 m/s/s, this is only an approximation and isn't necessarily always true when we do precise calculations. Since, by the Universal Gravitation Laws, acceleration is determined by the mass of each object and the distance between the objects, we can't necessarily use a "fixed" gravitational acceleration of 9.81, since as we are free-falling gravity's acceleration changes as a function of distance. In fact, even mass changes as we accelerate. I've always wondered how we could compute the true free-fall for an object of mass m as it falls. Any ideas?

I have a new theory My theory is that I will never reach the intellectual heights of people like Newton or Einstein so all I can do is ask questions to try and understand as best I can the theories that these people intellectually superior to me come up with. So I was just wondering if there is an upper and lower limit to how much energy a photon can have. I was thinking... if you travel away from a source of light, the faster you move away the more the light appears red shifted, it has a lower frequency and a longer wave length and so less energy. It still travells at the speed of light relative to you though. So if you were to travel ever faster you would …

Hi. Will a plastic linear fresnel lens focus a spot instead of a line if flexed across its line axis ? Just as reference: ---->

! Moderator Note this thread is a split from here http://www.scienceforums.net/topic/90145-thermodynamic-arrow-of-time-equating-entropy-and-disorder/ I completely disagree. The example is terribly misleading. The cup is a by-product of life, like an egg, or anything else that has been produced by a living being. And we know that living systems are self-organizing ones. Life create things that do not appear "just like that", as if Life was struggling against entropy. Let's take another example, say a melting iceberg. Of course you will not observe the sea water making back the iceberg. But the melted fresh water of the iceberg will mix with the salt w…

Hello, Can you guys help me with these two tasks : 1. I have two containers one above the other. In the first one, the fluid temperature is greater then the second one (let's say T1>T2).Containers have a valve between them, when you open it, fluids will mix. In which configuration mixed fluid will reach its equlibrium faster - if T1 is in the upper container or if T2 is in the upper container ? Or it does not matter? 2. I have two rods that are the same material, same length but different diameter, one much larger then the other. Both are heated to lets say T1. Which one will first get to T2 (lower than T1) ? I know its basic, but I will appreciate any …

I'm trying to understand thermodynamics in a more concrete and precise way and I'm planning to start by defining all the macrostates. One thing we do in thermodynamics is instead of calculating for every atom its momentum, energy etc. we define some microstates that are observable and measurable, right? So what all macrostates do we define? I tried to come up with macrostates without referring anywhere and here is the list:- 1) Volume - How much space the matter is occupying 2) Moles - How much matter is there in the volume 3) Pressure - How fast the matter is moving These are the only states I could come up. It seems as if all other states are derived f…

firstly the title is not the 'whole picutre' ! as a slight side-track from the Motor Physics thread, i wondered how a single magnet could have varying polarities. like i understand the phsyics of a normal bar magnet, but in this case we have a bar magnet (in a circular shape) which goes 'north, south, north, south' 4 times, resulting in 8N + 8S so a total of 16N+S (where N = north and S = south!). so if you look in this image: you can see the magnet i am referring to running around the outside of the metal 'disc'. if you take a normal bar magnet labelled N and S and take one end, e.g. N and run it around the outter circular magnet it is attracted/repell…

Guys, why in physics does the work done by the system have the POSITIVE sign, but in chemistry does the work done by the system have the NEGATIVE sign?

Where did I go wrong? Pascal is kg .metre ² . m sec². Why is it 1.019.. and not 1? Why is MPa not 100kg F cm² ? "1 megapascal [MPa] = 10.1971621297793 kilogram-force/centimeter²" If .5kg at 40msec² strikes on 1cm² is that 80 or 8MPa?

We know this conversion factor well. Then, is the efficiency about 100%? How do we prove it?

Hello all, the problem: A rod of length L, cross sectional area A, Young's modulus E and density rho moves with velocity v, hitting with its end on a rigid plane. Questions: 1. What is the maximum impact stress sigma? 2. How propagates the elastic stress wave in the rod (time and coordinate dependence)? An answer to question 1 could be sketched in this way: The impact stress is sigma = rho c v, where the wave velocity c is the square root of E/rho. This follows from the impuls change of the rod dp in a time interval dt, (i) dp = sigma A dt, substituting (ii) dp = rho A v c dt. Some explanations: Equation (i) invokes the stress sigma at the impacting cross…

I need answers: In 1D Motion; What is the Magnitude of Displacement? (Definition) Magnitude of Displacement <= Distance (True/False) (+Explanation) What is the Magnitude of average/instantaneous velocity? (Definition) Magnitude of Average/Instantaneous velocity <= Average/Instantaneous Speed (True/False) (+Explanation)