Reference frame Definition and 230 Threads

Problem If you throw a ball with velocity v at a wall, it rebounds with the same speed, v. What happens if you throw it at speed v towards a wall which is traveling towards you at speed w? What is your answer in the limit in which w is much larger than v? Answer Let us work in the frame of...

Hi, I'm quite new to relativity and I'm just going through some problems from past exam papers to prepare for an upcoming subject. The following question has me a little stumped: Betty is at the origin of her frame of reference. At a certain point in time, this also corresponds to the...

How can you have an inertial reference frame in which a body can remain at rest or move with constant velocity unless you postulate the disappearance of the universe? In the Michelson Morley experiment the Earth is not moving with constant velocity, it is accelerating. So the postulates of...

Homework Statement particle moves in a xy plane, force F is actiong on it, proove that there exists a frame rotating with angular velozity w.z in which the equations of motion of this particle will be x''=2wy' y''=2wx' Homework Equations m-mass xy-plane in which object moves F=-kr k=constant...

Homework Statement Consider a body falling from a tower in the northern hemisphere at approx 40 degrees latitude. The body is seen to have a displacement to the east. Explain the origin of this displacement qualitatively from the point of view of a non-inertial observer. What local effect is...

does an object with constant acceleration follow Newton's laws? with constant velocity? a stationary object? i think the last two are true, but I'm confused whether a constant acceleration (m/s/s) of whatever still applies to an inertial frame or is a noninertial frame? because in a sample...

Suppose an empty space and two points. The distance from point A to B is d = k . t^2 k=constant t = time The question is: Which point is an Inertial Frame of reference ? Suppose an empty space and two references frames. A is rotating at w with center B. But B is...

A ball is thrown with initial speed vo up an inclined plane. The plane is inclined at an angle(fi) above the horizontal, and the ball's initial vecity is at an angle (theta) above the plane. Choose the axes with x measured up the slope, y normal to the slope and z across it. Write down Newton's...

I am standing (yes, the question actually goes like this!) on a level floor at the origin of an inertial frame S and kick a frictionless puck due north across the floor. a.) Write down the x and y coordinates of the puck as functions of time as seen from my inertial frame. (use x and y axes...

Hello, Every definition of an inertial reference frame that I have read stated that it is a frame in reference in which Newton's laws are valid. But is it possible to define it in this way: it is a coordinate system that is not accelerating relative to some absolute reference point. Is there...

One way to attack a satellite in Earth orbit is to launch a swarm of pellets in the same orbit but in the opposite direction. Suppose a satellite in a circular orbit 500km above Earth's surface colides with a pellet having a mass of 4g. What is the KE of the pellet in the reference frame of...

A friend and I have been discussing what we think is an error in our textbook (either that or a misunderstanding on our part). The book gives an example in which two protons are initially traveling parallel to one another in the same direction with equal velocity. We think that since the...

Sorry for the trivial (and certainly already covered) question. Does a body's weight change with the ref. frame? If I had a very long scale on which the body can move without friction, would I observe the scale to sign different values according if I am stationary with the scale or with the object?

Hi I know that the following can never be done in the real world, but in theory, if the vectors of all particles, antiparticles, photons etc. in the universe could be summed, would that qualify as an absolute reference frame for that instant in time? Clearly each instant would have a...

I've seen several responses (and links) to the question "What happens when something is traveling at the speed of light" and understand that the answer is twofold. First no object can travel that fast because it would require an infinite amount of energy to acelerate physical objects to that...

dealing with non-inertial rotating reference frames, real forces such as the centripetal force need to be taken into account,or only the forces that can be really observed within the frame? because from the perspective of the rotating frame, objects should be at rest. it only appears logical...

SR is based on the postulate that all physics experiments yield the same results regardless of inertial reference frame? What was Einstein's basis for this assumption? What thought process did he go through to come to that conclusion? How could he know the speed of light was the same...

Does light still travel at c? Thank you.

Hi, I was thinking about an experiment that might demonstrate frame dragging via the equivalence principle. The apparatus consists of a rotating massive cylindrical shell within a vacuum. Near the inside and the outside of the shell exist two gyroscopes with their axis both...

i don't know why I am stuck on this question. It seems so easy, its making me sick. question: A man mounts a bathroom scale positioned on a skateboard such that it can roll without friction down an inclined plane of angle theta. He stands on the scale and reads off his weight as he is...

I've been reading Singh's Big Bang book, and towards the end he mentions that the CMBR was used to compute the relative speed of the Milky Way Galaxy, roughly 1,000,000 mph. This seems to suggest that the CMBR can be used as an absolute reference frame for any observer in the universe...

"Luboš Motl's reference frame" down?! Lately, I have tried on several occasions to access Lubos' web log.. the operation timed out every time. Anybody knows what's up? "Not Even Wrong" makes no mention of anything wrong (Peter Woit would normally, I guess, be the first one to voice out any...

Yes i understand that i posted this earlier, but it was perhaps just glanced over since it had got replies (by me trying to bump it up, sorry, again). But i seriously would like to know how to solve this question ANy help would be appreciated Note that i have copiedd the question exactly from...

Consider an object dropped from a height h above the Earth's surface. Observe the motion from the following two reference frames :- 1. The frame fixed to the Earth's surface :- Initially, Potential energy of the object = mgh Kinetic energy of the object = 0 Finally...

Is the use of a frame of reference for the sole purpose of defining a distance? Can distances be defined without a coordinate system?

I am not really sure I have the concept of an inertial reference frame down, can anyone help me?

There are various definitions of an inertial reference frame out there, but only one is really accepted by the physics community. In some places, you will see an inertial reference frame defined as a a reference frame in which Newton's law of inertia is valid. In some places, you will see...

In the measurement by the same quantum to compare, same quantum is the base in commonly, every measurement is more than twice progress to get a quantum. The interval in twice progress add some relativity action progress, the nature truly is part away. Relativity reference frame is reference a...

Suppose we are on a windowless bus that travels parallel to the Earth's surface at a constant acceleration with respect to the Earth's surface. How can a passenger in the bus determine the acceleration of the bus? We decided we could attach a mass to a string and attach the string to the...

To select a good reference frame to avoid some phys difficulty As the reference frame based in this universe, the universe is secret enough in phys, like first explosion, huge action between mass and so on. To select the reference frame from this universe is to meet some phys difficulty. It...