Accelerating Definition and 669 Threads

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 How much work must be done on a particle with a mass (m) to accelerate from rest to 0.897c (speed)? Homework Equations http://hyperphysics.phy-astr.gsu.edu/hbase/HFrame.htmlThe Attempt at a Solution Use work energy theorem. W=K2-K1 since K1 =0 W=K2 K2=E2-E1 (E1=0...

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?

Unfortunately this is due today, I will go work on another problem and watch these boards. And its not a last minute thing, I have been working on this since it was assigned... :cry: Homework Statement The lower block in Figure P8.28 is pulled on by a rope with a tension force of F = 28 N...

Homework Statement Zach, whose mass is 78 kg, is in an elevator descending at 11 m/s. The elevator takes 3.2 s to brake to a stop at the first floor. What is Zach's weight before the elevator starts braking? What is Zach's weight while the elevator is braking? Homework Equations...

1. A wedge of mass M slides on a frictionless horizontal surface; a block of mass m slides on the frictionless inclined surface of the block, which is inclined at angle theta to the horizontal. a) Using variables X for the position of the wedge, and s for the location of the block on the...

is the rate of expansion of the universe constant? or is accelerating or decelerating? can anything such as light ever catch the limits of the universe? and is it the space and the matter of the universe that's expanding or is it just the matter that's separating farther and farther apart into...

Homework Statement A ball initially at rest and constantly accelerating covers a distance of 10 metres during its third second of motion. What is its acceleration? Homework Equations No idea which equations I need. I'm guessing I need a = (v-u)/t The Attempt at a Solution I've got...

I recently read that there is apparently a repulsive force that acts over very long distances that is causing the expansion of the universe to accelerate. I was just wondering if there is any data that disprove the possibility that the big bang was not a singular event and that rather than...

Hello, I read this: Einstein's Special Theory of Relativity is valid for systems that are not accelerating. on this site: http://csep10.phys.utk.edu/astr162/lect/cosmology/gravity.html Honestly I cannot understand that. I have read the famous Gravitation by Wheeler and "Classical...

Now, I'd have to be using Newton's second law, here. Since there is no acceleration on the y axis: sum of forces_y = ma = 0 Now, as for the forces on the x axis, I thought I would need to do something like this, to find the tension of the rope. Let T = tension of rope. As the box...

So I'm new here, hopefully I'll post a lot more in the future. Anywho, not sure if this is the right place but I've been wondering about what would happen under a given scenario. Say that you have two large objects of mass such as 2 stars a substantial distance x away from each other. Take...

Homework Statement Box 1 is placed on box 2, which sits on the floor. Kinetic friction constant between the boxes, and the box 2 and the floor, is equal u. When box 1 is pushed with horizontal force F it starts to slide on box 2. At the same time, box 2 starts to move. What are the...

Homework Statement Hey guys, this is from Purcell 3.19 "Ions are accelerated through a potential difference V_0 and then enter the space between the semicylindrical electrodes A and B. Show that an ion will follow the semicircular path of radius r_0 if the potentials of the outer and inner...

Homework Statement Three blocks rest on a frictionless, horizontal table (see figure below), with m1 = 8 kg and m3 = 15 kg. A horizontal force F = 104 N is applied to block 1, and the acceleration of all three blocks is found to be 3.2 m/s2. Homework Equations W=mg F=ma Normal...

At the instant the traffic light turns green, a car starts with a constant acceleration of 1.3 m/s2. At the same instant a truck, traveling with a constant speed of 3.4 m/s, overtakes and passes the car. How far beyond the traffic light will the car overtake the truck?

hi all! So let's consider this situation: I am in inertial system and i have a standing rod with length Lo . Then there is a constant force F accelerating this rod. Will the rod's length shorten? Can i use the equation of length-contraction in case velocity is not constant (of course the...

A popular "Science" TV program said "The accelerating expansion of the universe does not apply to structures as small as the Solar System". Why not? Is there a boundary, marker, or distance that limits where the accelerated expansion begins? Thanks from an humble pupil, tfb

If charge radiates on acceleration,what would happen if we accelerate a neutral atom..will this radiate or not? this neutral atom also has electrons and protons which are charged so they should radiate but as a whole this neutral atom should not radiate?both are contradictory.. is this...

Homework Statement A disk accelerates with a constant angular acceleration of 2.0 rad/s2. If the initial angular velocity is 5.0 rad/s, what is the angular velocity of the disk after rotating though an angle of 11.0 radians? a = 2 rad/s^2 vo = 5 rad/s Theta = 11 rad Homework...

If I have a sphere (or another 3D object) and I apply a force to it through the centre of gravity, it will accelerate according to F=ma If I apply a force to the sphere which doesn't act through the centre of gravity, I apply a turning force according to T=F*d How do you figure out how much...

Is there any other force that is acting upon an accelerating electrically charged large body, in free space? Is Lenz's law applying in this situation? I read somewhere that J.J. Thompson observed that is harder to move an object when is charged than when is neutral. If there is a resistive force...

Homework Statement A pair of fuzzy dice is hanging by a string from your rearview mirror. While you are accelerating from a stoplight to 28m/s in 6s, what angle does the string make with the vertical? Homework Equations g, accel. of car is 4 2/3 m/s^2 The Attempt at a Solution...

Homework Statement This question basically tries to investigate the feasibility of using a rocket engine to acclerate a spaceship to relativistic speeds, as with any rocket engine fule is ejected at high velocity and spaceship accelerates to conserve momentum. only that in this situation, the...

What is the value of acceleration of universe? like Earth's gravitational acceleration is around 9.8 m/s2..has anyone found this value?

Homework Statement A 6000kg helicopter accelerates upward at .6m/s^2 while lifting a 1500kg car. What is the tension in the cable (ignore the cable mass) that connects the car to the helicopter? Homework Equations F=MA The Attempt at a Solution Alright... so here's what I've been...

A 2.3 103 kg car starts from rest and accelerates along a horizontal roadway to +17 m/s in 21 s. Assume that air resistance remains constant at -500 N during this time. Find (a) the average power developed by the engine and (b) the instantaneous power developed at t = 15 s. I am...

1. Why does a crate on an accelerating truck accelerate backwards proportional to the amount of kinetic friction? I don't understand why the crate accelerates backwards as if kinetic friction was the only force acting on it. 2. Homework Equations : F=ma

hi..i know the faraday's electromagnetic induction e=-dФ/dt...supposing there is an coil of wire and i am accelerating magnet through the coil of wire and this will produce emf because accelerating magnet results in change in magnetic field...my question is how to relate this acceleration a and...

If I hang a pendulum on the ceiling of an accelerating train (with an initial angular displacement), how would the angular acceleration be affected? My intuition told me that the angular acceleration of the pendulum should be affected by the acceleration of the train. But...whether the...

what is the formula for the acceleration felt by an accelerating object? I've spent days googling and can't get a straight answer. some say its the derivative of proper velocity with respect to proper time but others say its the derivative of proper velocity with respect to coordinate time...

In the Davisson-Germer experiment using a Ni crystal, a second-order beam is observed at an angle of 55°. For what accelerating voltage does this occur? Thanks

Homework Statement http://pyrofool.googlepages.com/lab25.gif A 2 kg mass and a 3 kg mass are on a horizontal frictionless surface, connected by a massless spring with spring constant k = 140 N/m. A 15 N force is applied to the larger mass. How much does the spring stretch from its...

How are torques computed about an axis when the axis (and the attached body) are both accelerating at the same rate? For example, if a car is in free fall with the doors open (with the rear end of the car pointing towards the ground) will the doors shut themselves due to torque? Or, is the...

Accelerating Wedge Problem, Help! Homework Statement A 45degree wedge is pushed along a table with constant acceleration A. A block of mass m slides without friction on the wedge. Find its acceleration. As always, find your result in an inertial frame. Homework Equations (x - X) =...

A festival rocket is ejecting 0.05 kg of gases per second at a velocity 400m/s The accelerating force on the is? The formula given in the book is F=dp/dt What does the formula mean:confused:

Two observers, A & B, are moving apart at constant velocity V. At distance D, B sends a pulse to A which arrives T seconds later. If B were instead accelerating at a rate such that he attains velocity V just when he is at distance D, and sends a pulse at this instant (while still accelerating...

"Behavior of light accelerating" Imagine a spaceship which has got a small lightbulb standing on the floor. You turn on the lightbulb and the light shoots towards the ceiling, but before the light reaches the ceiling the spaceship accelerates a bit and stay at some velocity. My question is...

I have some questions about one of the old elevator/spaceship thought experiments. 1. If I am on a spaceship that is far from any massive bodies and is accelerating upward (from my point of view) uniformly at g, is the spacetime in my ship curved or flat? 2. If a beam of light enters...

Homework Statement A Cyclotron is accelerating proton, where the applied magnetic field is 2 T, the potential gap is 100 KV, then how much turn are required for a kinetic energy of 20 MeV... (a) 300 (b) 200 (c) 150 (d) 100

Homework Statement 19: There is a block a, 100kg and block b 10kg on the right towards the top of block a, hanging in mid air. a force is applied to these two blocks on the left, pointing to the right. THe problem is as follows: What force must be exerted on block A in order for block B not...