Accelerating Definition and 654 Threads

Hypothetically, how long would it take to get to the speed of light at 1 G of acceleration? Is this simple math or does relativity some how get into the calculation? Einstein: You do not really understand something unless you can explain it...

Homework Statement What is the coefficient of friction between the road and the wheels of a 1400kg truck accelerating at 2 m/s/s if the force applied by the engine to the wheels is 4000N. Homework Equations Fn = m * g Ff = mu * Fn The Attempt at a Solution I do not know how to...

Homework Statement A proton (q = 1.6×10−19 C, m = 1.67×10−27 kg) moves at 300 ms−1 along a line midway between the x and z axes. There is a magnetic field of 1T along the x axis and an electric field of 2000 Vm−1 along the y axis. What is the force on the proton and what is its acceleration...

So I've been doing a mini investigation into the power draws on a car accelerating up to a aroudn 100 mph and came up with this graph. I never really thought about it before but it appears from this graph that inertial forces (here i have only taken into account the acceleration of the main...

Homework Statement A block of mass m is initially at rest at the top of a ramp, inclined at angle θ to the horizontal. The coefficient of friction between the block and the ramp is µ. The ramp is now pushed at acceleration a to the right. For what range of value of a will the block start...

Using Einstein's train thought experiment, suppose a train is accellerating exponetially so that the engine remains forever ahead of a beam of light without it ever reaching the speed of light. V = c[ 1 - e^(-t)] for the train The light would approach the engine but never quite reach it...

My textbook says that since the electrons are accelerated to the right in a CRT the field direction is to the left. This leaves me confused, because according to this model the field lines are pointing out from the electrons instead of pointing into the electrons. I thought that field lines are...

Hi! I'm doing physics project and I'm stuck with a really awful paradox.:confused: Universe appear to be flat (nearly), so it should expand forever (the critical universe). On the other hand we've got acceleration of the universe so open model. Which model is the right one?

I need to be able to calculate the final velocity of an object accelerating towards a mass from a distnce with an initial velocity. From my little knowledge of calculus, I am only a junior in high school, i have figured out that this is probably a derivitive problem. But i have no knowledge of...

I just posted this on the bibliography links thread. Thought it would be good to post for discussion as well. http://arxiv.org/abs/1002.4278 Entropic Accelerating Universe Damien A. Easson, Paul H. Frampton, George F. Smoot 10 pages, 1 figure (Submitted on 23 Feb 2010) "To accommodate the...

Are objects in space moving apart at an increasing rate relative to one another, or is the 'space' between them expanding? For example, using red-shift to explain the differential causes: If an object is moving away from Earth, the electromagnetic waves it emits are red-shifted. This would be...

Homework Statement A light spring force const. k hands from ceiling of an accelerating lift with a block of mass m attached to its bottom end. Block is held stationary (in lift frame) with the string at its equilibrium length while the lift is accelerating at a rate Ag where A is between -1...

This is not an actual problem from my class. All our problems involved an elevator going upward (both accelerating and decelerating). But I am curious if an elevator cable would have the same FT if the elevator was decelerating downward at -3 m/s2 as it would accelerating upward at 3 m/s2 ? I am...

Homework Statement The spacing between two traffic lights is 300m. A car can accelerate from rest with a constant acceleration of 4 m/s2 and decelerate at 8 m/s2. (Ignore the reaction time of the deriver.) a) What is the maximum speed the car can reach and still be able to stop right at...

Hi! Well, I have a problem, I'm writing Extended Project For Applied Science about Death of the Universe, I am stuck. I am really desperate so I decided to put it on forum. First: The Universe is accelerating so, according to Lorentz's Factor, its mass should be increasing m = \gamma m_{0} =...

Ok so i have the distance traveled of an object assuming air ressistance is 0 and the distance traveled with air resistance included as well as the acceleration of the object, how would i calculate the coefficient of air resistance? Thanks

If vacuum energy accelerates the expansion rate of the universe and that produces a larger universe with more vacuum energy to accelerate the expansion is there a positive feedback loop here? Does the expansion rate grow exponentially? Do we get another big bang? Is it a big bang in it's...

Homework Statement Two 3.0 kg blocks on a level frictionless surface are connected by a spring with spring constant 1000 N/m. The left block is pushed by a horizonal force F to the right. At time t=0 seconds, both blocks are moving with velocity 3.2 m/s to the right. For the next second, the...

Homework Statement Prove that the upward velocity of a rocket of initial mass M0, which is propelled by fuel burning at a rate of R kg/s, is given by vy = uex * ln[M0 / M(t) ] - g * t. uex is the speed of the exhaust gas relative to the rocket and M0 is the initial mass (rocket + fuel). Also...

Homework Statement If the balloon in the diagram drawn below is accelerating upwards at 0.40 m/s2, calculate the tension in each piece of rope. Assume that the rope has no mass. http://img261.imageshack.us/img261/964/capture2gm.png http://img261.imageshack.us/img261/964/capture2gm.png...

This question concerns a paradox I've come up with in GR. If somebody could tell me where it breaks down, I'd be much obliged. Thank you! Assume there is spaceship A hovering above a black hole, and spaceship B further away from a black hole The black hole, A, and B are all lined up. (The...

If anyone could help me with these two questions that would be great. 1.A freight train has a mass of 1.20E+7 kg. If the locomotive can exert a constant pull of 8.03E+5 N, how long does it take to increase the speed of the train from rest to 70.6 km/hr? 2.A football punter kicks a...

Homework Statement An electron is accelerated through an electric potential to a kinetic energy of 18.6 keV? Homework Equations KE=1/2mv^2 The Attempt at a Solution

A point charge moving at constant velocity causes unconstant changes in the electric field. Won't that generate an electromagnetic wave?

Homework Statement A positive test charge is brought near a stationery fixed point charge. The positive test charge is then released. How does the test charge move after it is released? a) Constant Velocity b) Increasing Acceleration c) Decreasing Acceleration d) Constant Acceleration...

Homework Statement A particle travels along a path C in R^3 which velocity v(t) =<t^2, cos(pi*t), t> at time t. Assume that the particle's initial position is at the point p=(1, 0, -1). Find all times t at which the particle is accelerating in a direction that is perpendicular to the plane...

If you are told an object is accelerating, what should you conclude? Choose all that apply. The object is speeding up. The object is slowing down. The object is changing direction. There is a nonzero net force acting on the object. The object is moving with a constant velocity. Please...

Assume that a rocket ship leaves the Earth in the year 2100. One of a set of twins born in 2080 remains on the Earth (inertial frame); the other rides in the rocket. The rocket ship is so constructed that is has an acceleration g in its own rest frame (this makes the occupants feel at home). It...

I was just reading an article about dark matter and the expansion of the universe and thorught it sounded like a bit of a bodge so I began thinking about what else could cause the acceleration and came up with this idea. Perhaps someone could tell me why it's wrong? Is it not possible that...

I read an article about 2 weeks ago (another astronomy major sent it to me, but unfortunately I'm having trouble find it, when I talk to him again I'll get the source and post it) that proposed an alternative to the universe expanding. The article stated that the reason we see light redshifted...

Simple question. I would like to know if there is a definitive answer , consensus in the field, on the question of the measurement of light in an accelerating system. Whether one way measurements from the front to the back and vice versa would result in (c +v) = (c-v) = c as usual...

Hi I just encountered a couple of concepts I was unaware of in another thread. As the thread was an intence discussion on another topic I am posting this here. So any insights or references regarding this would be appreciated. Explanations , interpretations or comments...

If you were to drop a penny down an elevator shaft that was infinite in the downward direction, what would begin to happen when the penny is accelerated by gravity to the speed of light or at least very close?

I'm trying to get an equation to calculate how fast an automobile would be going to cover 500 feet if it takes the vehicle 8.9 seconds to go from 0 - 60 mph.

From some previous discussions in this forum I had gotten the idea that under the equivalence principle, observations inside a small room sitting on the surface of a planet should be seen as equivalent, not just to any ol' accelerating room in flat spacetime, but to a room undergoing Born rigid...

Just a physics buff so bear with me, this has been bothering but I am sure there is a simple answer. I watch a lot of physics and science programs on TV. When discussing red shift the explanation is that the light from objects that a further away is more red-shifted than light from closer...

Homework Statement A block rests on a wedge inclined at angle \theta . The coefficient of friction is \mu . The wedge is then given a horizontal acceleration a. Assuming that \tan (\theta) < \mu , find the minimum acceleration for the block to remain on the wedge without sliding...

Accelerating galaxies? If Gravity is constantly pulling galaxies toward each other, why are they accelerating away from each other? ::::::::::::::::::::::::::::::::::::: In Love Prys die Heer!

A serious flaw in the Planetary model was that it theorized that electrons accelerated around the nucleus which would cause them to continuously lose energy as EMR and crash into the nucleus. The Bohr model also I think, fails to explain WHY the accelerating electrons don't emit EMR . How does...

Would a signal sent from a transmitter, traveling at constant velocity toward an observer, arrive at the same time if it were accelerating toward that observer? The signals are sent at the same relative distance from the observer. Would the result be the same if the transmitters were receding...

Homework Statement The horizontal surface on which the objects slide is frictionless. The acceleration of gravity is 9.8 m/s2. Three blocks are sliding on a frictionless horizontal surface: Fℓ----->[Block1-1kg][Block2-7kg][Block3-4kg]<--Fr If Fℓ = 29 N and Fr = 3 N, what is the...

Hello, You've all probably seen the classic Blasius solution concerning the thickness of a boundary over a flat plate. This problem though assumes that the free stream velocity is constant. http://www.see.ed.ac.uk/~johnc/teaching/fluidmechanics4/2003-04/fluids9/2-dboundary.html I am...

What the title implies, with the discovery that the universe is expanding, are we observing the systems becoming harder to see? You'd think that with the speed of the objects and the distances involved, things like brightness and actual size would be getting reduced...

I wanted to know a bit more about the fact that in the presently accelerating expansion of the universe the Hubble constant is still decreasing. When the universe was decelerating the Hubble constant was decreasing. It is still decreasing in an accelerating universe. Does that mean the Hubble...

Homework Statement A pendulum with string length L hangs inside a boxcar that is rolling down an incline at an angle Beta. The pendulum swings to a maximum angle Theta. Ignore friction, assume Beta and Theta are small. How far from the vertical will the pendulum swing to the left while...

I have been asked to come up with a formula by a rather persistent person who is Addiment that a wheel on an accelerating treadmill attached to a mass (such as a car) would not produce enough translational force to move the Car. The Question as posed to that persons; Please forgive any and...

Homework Statement you and your friend have just loaded a 200kg crate filled with priceless art object into the back of a 2000kg truck. As you press down on accelerator, a force, Ft, propels the truck forward. What is the max magnitude the force can have without the crate sliding? The static...

Hey, I am doing a question for a physics assignment, and it asks me to find the "wavelength of radiation produced by a proton in a cyclotron with a radius of 0.500 m and magnetic field with a magnitude of 0.200 T." Unfortunately the textbook doesn't give me an equations that have anything to do...

A particle has a constant acceleration in a laboratory from 0 to 0.5c in 3 seconds. What time elapses for the particle (i.e. what is the proper time for the particle)? Hint: (you will have to integrate the proper time of the particle over the 3 seconds as measured in the laboratory frame)...

The question is: A rocket has a constant acceleration in a rest frame that is 0 to 0.8c in 4s. What is its proper time? This question I found, I guess I'll have to use integration but don't have a clue where to start off. Could you give me some ideas please?