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General and Special Relativity
Relativity is the theory stating that all measurements depend on the relative motions of the observer and the observed. The theories of general and specific relativity were both proposed by Albert Einstein.
813 Questions
Who developed the equation e equals mc2?
The equation E=mc^2 was developed by physicist Albert Einstein in 1905 as part of his theory of special relativity. It describes the equivalence of energy (E) and mass (m) and the constant speed of light (c) in a vacuum.
If a force table was not level what is the affect?
Then a component of the force of gravity would add to any force with a component
parallel to the table's gradient, and, in the technical jargon of Newtonian Mechanics,
the results of the experiment would become garfed up, i.e., corrupted.
One definition of 'work' is [ (force) multiplied by (distance through which the force moves) ].
If this guy simply holds the sheet of drywall motionless, then no work is done on the sheet of drywall.
He's doing a lot of work, though, constantly making the small internal muscular adjustments needed
to keep the sheet motionless.
Is it possible to have a negative degree minute second answer?
Sure. That just means that when you set up the problem, you indicated angles
to be measured in a certain direction from the reference point, and the answer
turned out to be an angle in the other direction from the reference.
Why does a stationary train appear to be moving?
Because there's no such thing as "really" stationary or "really" moving. If the
distance between a point on one train and a point on the other train is changing,
then a person on either train says that the other train is moving, and both of them
are correct.
A "stationary" train only appears to be moving if the train you're on is moving
relative to that one.
How did Albert Einstein discover the special theory of relativity?
Albert Einstein developed the special theory of relativity by considering the behavior of light in relation to moving observers. Through thought experiments and mathematical calculations, he derived the famous equation E=mc^2, which describes the equivalence of mass and energy.
A charged insulator can be discharged by passing it just above a flame explain how?
Passing a charged insulator above a flame can create ions in the air near the insulator due to the high temperature of the flame. These ions can neutralize the charged insulator, allowing it to discharge. The process relies on the ions transferring their charge to the insulator, thereby removing its excess charge.
A second is a unit of time that is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium-133 atom. In more practical terms, a second is a relatively short duration that helps us measure time intervals in our everyday lives.
How does a bouncing ping-pong on a train explain the concept of relativity?
When a ping-pong ball bounces on a moving train, its motion appears different to an observer on the train and to an observer standing still outside. This illustrates how motion is relative and depends on the observer's frame of reference. Similarly, in the theory of relativity, the laws of physics are the same for all observers, regardless of their relative motion.
What is speed of light affected by?
The speed of light depends on the medium through which it passes. The fastest that light can travel is the speed of light in a vacuum (c), which is 299,792,458m/s. The permittivity and permeability of the medium through which it passes are what reduces the speed of light.
For example, while the speed of light in air can be simplified to being approximately 3*10^8m/s, in an optical fibre, it is reduced to approximately 2*10^8m/s, that is, two thirds of it's speed in a vacuum.
Light will easily propagate through an insulating medium, though will not do so through a conductor, as the electric and magnetic fields generated by the electromagnetic radiation will interact with those of the conductor.
Which quantity in the equation E equals mc2 will most likely be the smallest?
The quantity that is most likely to be the smallest in the equation E=mc^2 is the mass (m). Mass is typically much smaller than the speed of light squared (c^2), and energy (E) can be significant due to the speed of light's large value.
How did scientists apply albert Einstein equation e equals mc?
Scientists don't actually do the applying. But I guess the most noticeable, most
widely comprehended demonstrations of " e = mc2" have been the atomic bomb
and the hydrogen bomb.
What does the theory of relatively do?
The theory of relativity, proposed by Albert Einstein, describes how the laws of physics are the same for all non-accelerating observers and explains the nature of gravity as a curvature of spacetime caused by mass and energy. It consists of two main branches: special relativity, which deals with objects moving at constant velocities, and general relativity, which incorporates gravity and acceleration.
What does the c in e equals mc2 mean?
The "c" in E=mc2 stands for the speed of light, which is approximately 299,792 kilometers per second. This equation, proposed by Albert Einstein in his theory of special relativity, relates energy (E) to mass (m) and the speed of light (c).
What is the applications of angular momentum?
Angular momentum is used in various applications in physics and engineering, such as in analyzing the motion of objects in rotation (like spinning tops or satellites), understanding the behavior of gyroscopes, and explaining phenomena like the conservation of angular momentum in celestial bodies. It is also crucial in quantum mechanics for describing the rotational properties of particles.
The equation E equals mc2 stands for?
The equation E=mc^2 stands for "energy equals mass times the speed of light squared." It expresses the concept that energy (E) and mass (m) are interchangeable, with the speed of light (c) acting as the conversion factor. The equation is a fundamental principle of physics, demonstrating the relationship between energy and mass.
What is the constant speed at which light and other forms of radiation travel?
The speed of light, which is approximately 186,282 miles per second (299,792 kilometers per second) in the vacuum of space, is a constant speed at which light and other forms of radiation travel. This speed is denoted by the symbol "c" in physics.
If you are *not* dealing with special relativity and its effects, then the answer becomes far more simple.
If you are not moving and are standing on the ground, then you see a train moving past you a fast speed. In this case, the reference "frame" (not necessarily a point) is you and the object being described is the train.
If you flipped the roles, then it would be someone on the train watching you as the train moves. However, since it is from the train's perspective, it does not appear that the train is moving, but rather that you are moving away from the train, along with the rest of the world that passes the train by. This is described as the train being the reference frame and you would be the object described by the train.
This is, again, just Galilean relativity. Special relativity puts a few twists on it and has some additional effects.
What is meant by Electrodynamics of moving bodies?
Electrodynamics of moving bodies refers to the study of how electric and magnetic fields interact with objects in motion, according to the principles of electromagnetism. It involves understanding how these fields are affected by the relative motion of objects and how they can induce forces and currents in those objects. This concept is fundamental in understanding phenomena like electromagnetic induction and relativistic effects.
If a plant was growing bent over towards the light how could you make it grow straight again?
You can rotate the plant regularly to ensure even exposure to light on all sides. You can also gently tie the plant to a stake for support, or prune it to encourage upright growth. Additionally, ensure the plant is receiving enough light to prevent it from bending.
Why simultaneous events for one observer may not be simultaneous for another observer?
This is because light requires time to travel from point A to point B and when observed from a different inertial frame of reference, the two events may not appear to be simultaneous.
Inertial reference frame: Inertial refers to the frame (an area in which the laws of physics work the same for all observers within it) which is neither accelerating nor decelerating. Example: Earth
What is a simple definition of Einstein's theory of relativity?
A very simple definition of special relativity would be: 1. Nothing travels faster than light. 2. Light is always measured at the same speed (roughly 186,000 mph) no matter how fast you are traveling or the direction you are going. 3. The faster you travel, the slower time moves, the heavier you get and longer things become shorter. However, the hardest part to grasp is the fact that as you move, nothing to you is different. Your clock will still tick away at the same rate. An observer, however, would notice your clock running slower. You would notice the observer's clock runining slower while they would be seeing things perfectly normal It's all relative to the observer. General relativity incorporates gravity into the equation and shows how gravity effects time, bends light and thus effects time. A clock for intance on the ground next to the Empire State building will run faster than a clock on the top of the building because the pull of the earth causes clocks to run slightly slower then a clock that is further away from the center of the planet.
The question states an incorrect premise. As an object approaches the speed of light, neither the object nor light "goes slower". At relativistic speeds (speeds of about 1/100 of the speed of light or faster), the faster a body travels, the slower time passes for that body compared to a "non-moving" frame of reference.
Light is measured to travel at the same speed for all observers, no matter what the observer's speed is. For example, suppose you were in a space ship traveling at 1/2 the speed of light, and that space ship was racing toward a star. You would measure the light coming from that star at c, the constant speed of light. Now suppose your friend was in another space ship which was "stopped". Your friend would measure the same light coming from the same star at the same speed of c. The difference between you and your friend is your friend would age more quickly than you would, because time passes more slowly for you while you are traveling at relativistic speeds.
It is also true that, as a body approaches the speed of light, it develops something called relativistic mass. So you, your space ship, and everything in it gets heavier when you travel at 1/2 c. Because the space ship gets heavier, it becomes harder to push (it has greater inertia), and therefore it is more difficult to accelerate the space ship further to make it go even faster. So it is true that, as you approach the speed of light, the harder it is to approach the speed of light. The mathematics predicts that, at the speed of light itself, your relativistic mass is infinite1, and so is your inertia, therefore you can never "push" something to make it actually go as fast as the speed of light.
Light itself is a bit of an enigma. A photon - a light particle - has zero mass, but it does have momentum. Zero mass also means zero relativistic mass, allowing the photon to travel at c. In fact, not only can a photon travel at the speed of light, it must travel at the speed of light - a photon exists only while travelling at the speed of light - it ceases to exist if it stops or slows down.
1 Relativistic Mass = Rest Mass / SQRT ( 1 - v2/c2), v is the velocity and c is the speed of light.
Answer:
I think I know where this question is coming from, but you made a bit of a confusion perhaps? Basically, the closer you get to the speed of light, the slower time goes? Is that what you meant to say? Relativity is very hard to get your head around, because you need to drop the concept of velocity altogether, and only think of relative velocity, and time, and even length in the direction you travel in (I did say it would be weird!). Light will ALWAYS overtake you at 300000000m/s. It doesn't matter how fast you go, or how slow you go relative to the source of that light, it will always, if travelling through a vacuum, travel at the speed of light given, and this value is a constant value called C. Its the space speed limit that is policed by the laws of physics. But, if you did travel very fast (close to C), there would be a time dilation relative to people here on earth. And this was first discovererd when they realized that particles that came down to earth from the upper atmosphere had a half life such that they should have decayed before they made it to the ground, however, because their velocity relative to the earth approaches C, they actually lasted longer! This same principal would apply to humans, so it would be possible to sit in a space craft, go close to C, come out 1 year later, and for all your friends and family and everyone you know to have grown old, whilst you'd only be 1 year older, because more time would have passed on earth than would have passed in your space craft, and this is called the time dilation effect.
We don't know why it is that light is a constant and everything else is relative. Our understanding does not reach there. And we can't go faster than light because of the "conversion" of the energy of acceleration. It acts in a way that requires continually more energy be applied in an attempt to push an object closer to the speed of light. The more energy we apply, the more "resistance" to acceleration we'll encounter. And we cannot ever push the object to the light speed threshold. It is a real "barrier" in that sense.
As regards time moving backwards, that is a speculative concept. If time slows down for an accelerated frame (for someone moving really, really fast), it might "stop" and "move backward" as the frame moves to and through c's barrier. (The speed of light is often seen designated by c.) It might be possible to move back in time, but we don't know if this is possible. We have no physical way to test it now, and one is not on the horizon. However Einstein said that it takes an infinite amount of energy to achieve light speed and there is no such thing, see theory of relativity for more info
What voltage is needed to accelerate electrons to 1.5 times the speed of light in a CRT?
It is not possible to accelerate electrons--or anything else--to the speed of light, much less to 1.5 times the speed of light.
Nominal operating voltages for a CRT range from a couple of thousand volts to a few tens of thousands of volts, depending on the application.
