Relative Definition and 1000 Threads

Homework Statement Say a human is moving through space with constant acceleration due to gravity. There are no external forces/torques on the body other than the force of gravity. The person applies an internal torque at some joint, let's say the knees, so that they bend. Assume the rest of the...

Homework Statement Two solid pieces, one of steel and the other of aluminium when completely immersed in water have equal weights. When these solid pieces are weighed in air, aluminium seems to weigh more. Why is this so? On what factors in this being decided?[/B]Homework EquationsThe Attempt...

Homework Statement A lift in which a man is standing is moving upwards with a speed 10 m/s. The man drops a coin from a height of 4.9 m and if g = 9.8 m/s2 - then after what time does the coin reach the floor. Homework Equations x = 0.5*g*t2 x = ut + 0.5*g*t2 The Attempt at...

Here is a thought experiment. Imagine Schrodinger's cat... in the traditional model, there is a single observer outside the box, and the observer creates an entanglement with the catbox device which reveals the quantum superposition of the enclosed cat. The cat is said to be in a superposition...

Homework Statement Cars A and B are traveling on adjacent roads. Car A travels at a speed of 70 mi/h in the positive y direction, and its acceleration is zero. Car B travels along a circular path of radius 0.7 mi, and has a velocity of 50 mi/h at an angle of 30 degrees right of vertical. Car...

Why is milk with a higher relative density better than one with a lower one.

In the wikipedia page of Lorentz Transformation (http://en.wikipedia.org/wiki/Lorentz_transformation#Lorentz_transformation_for_frames_in_standard_configuration) it's said that The problem I'm having here is that while taking Lorentz Transformation as true, I failed to verify the statement...

Homework Statement A slotted link AC is is driven by the peg P connected to a rotating disk. Point A is fixed. Determine the link's angular velocity, \omega_{ac} and acceleration, \alpha_{ac} when the angular velocity and acceleration are \omega and \alpha , respectively. \omega = 6...

Homework Statement Aircraft A is flying NorthWest at 800km/h. Aircraft B is flying in a circular, anticlockwise holding pattern, radius of 5km, at 400km/h.Show that the acceleration of A relative to B is A(A/B)= 2.469cosθBi+2.469sinθBj m/s2 Homework EquationsThe Attempt at a Solution I know...

Okay, this is my first post, and I'll have you know that I'm just an amateur. So, I'm not going to get into any complicated mathematics. So basically, is time relative to position? Hypothesis: Yes, it is. Reason: Well, here's a dumbed down version. The Earth's rotation around the sun is what...

Homework Statement A rocket is moving in a gravity free space with a constant acceleration of 2m/s2 along +x direction. The length of chamber inside the rocket is 4m. A ball is thrown from the left end of the chamber in +x direction with a speed of 0.3m/s relative to rocket. At the same time...

Homework Statement A certain quasar recedes from the Earth with a speed of .87c. a jet of material is ejjected towards the Earth at .55c relative to the quasar. find speed of ejected material relative to the earth Homework Equations u = u'+v / 1 + u'v/c^2 The Attempt at a Solution guessing...

When a book which is on table is pushed, it moves in the direction we push and the work done by us is positive and the energy gained by the body is also positive. But consider the frictional force. The work done by it is negative. So in one incident force is both positive and negative depending...

When a spaceship accelerates to 1.000 kmh, the effect of time dilation is tiny. But what happens if this spaceship accelerates in an inertial frame whose total speed is much slower or whose time goes much faster, will the time dilation effect be the same? If the spaceship travels in a inertial...

I have been asked about time dilation which I thought I understood, but maybe you can help me provide an answer? If a spaceship is traveling at 0.866c then time will slow by a factor of 2 due to the speed the spaceship has. Why? If it is alone in space, light years away from any other body...

In relativity of simultaneity, two spatially separated events are time relative as to the order in which they might occur to the observer (time is relative). However, if the two events are causally connected, the order is preserved in all frames of reference...

Homework Statement Consider the core of dimensions given in example 5-1. A coil requires an inductance of 23.6μH, a maximum current of 4A is allowed, and flux density is not to exceed 1.3T. Calculate the required relative permeability, μr, of the magnetic material that should be used. (HINT...

I'm wondering .. if there is an argument could prove that the relative speed of two inertial frames must be the same .

Homework Statement An ant with a velocity of 20mm/s [W] crawls on a stick that is being dragged [W25 N] at 50mm/s. what is the velocity of the ant relative to the ground? Homework Equations Let A = ant, Let S=stick, Let G=ground, Let N and W be positive. Vag=?, Vas=20mm/s [W], Vsg=50mm/s[W25N]...

Hi, everyone. I'm new here so I'll introduce myself: I'm not a physicist, just a physics enthusiast. Although I have studied some physics at school and college, I've never been taught relativity, which I've kind of learned about on my own. My question might seem stupid to you, and I apologise...

I'm using the the Doppler formula to calculate the relative velocity between the approaching and receding filaments of the crab nebula: Δλ/λnaught = v/c Change in wavelength/ wavelength = velocity/ speed of light I have reworked the formula as v= c(Δλ/λnaught) When I plug in the values I get...

When an object is flying to the Earth and it's increasing it's speed through gravity, does a remote observer see this increase of speed too, or will he see the object moving at a constant speed? And another question: Is there any time dilation by the remains of an object that hits a planet...

Homework Statement Particles ##a## and ##b## move in opposite directions around a circle with angular speed ##ω##. At ##t = 0## they are both at the point ##\vec{r} = l \hat{\jmath}## where ##l## the radius of the circle. Find the velocity of ##a## relative to ##b## Homework Equations...

So, I recorded the result of a LabQuest 2 Vernier Magnetic Field Sensor on different points of a plane, with a solenoid in middle with a 5 amp current running through. I want to compare my results with theory, but have no idea what equation I'm supposed to be using. I assumed it was B = μ0ηI/r3...

Hi Guys, Don't know if I posted at the right place... can anyone tell me how to calculate the relative permittivity/permeability of a 3D microwave metamaterial for Q-band (wavelength ranging from 6mm to 9mm)?

Homework Statement If ≡(mod), ≡(mod),and gcd(,)=1,provethat ≡ (mod ). Homework Equations If ≡(mod)→n|ab-cd ≡(mod)→n|b-d gcd(,)=1→ relatively prime. So bx+ny=1 Need to show n|a-c→a-c=nw The Attempt at a Solution If n|ab-cd, then nk=ab-cd If n|b-d, then nl=b-d If n|ab-cd AND n|b-d, then...

I am looking for way how to do relative calibration of light sensor (PMT). I would appreciate any suggestions or links to sources with description how to do it in very simple (understand also cheap if possible) way. For example. Let say that I have integration sphere with two outpust. I have...

Homework Statement if gcd(a,b) = 1, show that gcd(ac,b) = gcd(c,b) Homework Equations gcd(x,y) = xm + yn for integers n and m The Attempt at a Solution ax + by = 1 gcd(ac,b) = d gcd(c,b) = g ac = dr b = ds c = gm b = gn I've been setting up equations and rearranging things but can't make...

Homework Statement A fisherman wishes to cross a river to the shore directly south of his position. The river is 400 m across, and the fisherman's boat is capable of a speed of 2.5m/s. If the river's current has a velocity of 1.5m/s [W], determine a) the time it takes the fisherman to cross...

Homework Statement Let a and b be relatively prime. Show that gcd(a+b,ab) = 1 Homework Equations ax+by = 1 for some integers x and y The Attempt at a Solution I set gcd(a+b,ab) = d. I'm now trying to show that d = 1 using elementary algebra techniques. a+b = rd ab = sd ax + by = 1I'm kind...

Since relative velocity time dilation is due to an increase in velocity, with a person moving faster moves through time slower than those on earth, does it follow that it's possible to move slower than the Earth and therefore move through time faster than them? Because the Earth is moving...

Consider a rod AB rotating about one of it's end A with angular velocity w. Now angular velocity of each point of the rod is same i.e. w. But if we have to find the relative angular velocity of the end B w.r.t. mid point of rod, what it will be? Will it be zero because, w-w=0 or first we...

2. (a) is the question I'm stuck with Homework Equations I know that 3m/s is the Velocity of the man relative to the water and the Velocity of the man is 8m/s and is represented by the vector pointing in the direction theta downstream but I just can't get my head around this question, probably...

I am studying the relative speed equations but I confused in one point. We need (at least) how many observers to calculate relativistic speed equation. Three or two.

Homework Statement An 82-kg lumberjack stands at one end of a 380-kg floating log, as shown in the figure (Figure 1) . Both the log and the lumberjack are at rest initially. If the lumberjack now trots toward the other end of the log with a speed of 2.7 m/s relative to the log, what is the...

I'm still very early on in my reading, so forgive me if this question isn't coherent. In the "historical introduction" section of the 1920 University of Calcutta translation of the original papers of Einstein and Minkowski available via the MIT online archive, mention is made of the fact that...

I'm having trouble understanding how the lorentz transformations are posed intially. Why can different observers agree on their relative velocity? I don't understand why this velocity is exempt from all of the other relativistic phenomena that occur. Also, in the initial derivation, I'm told...

Homework Statement "To illustrate this principle, consider a plane flying amidst a tailwind. A tailwind is merely a wind that approaches the plane from behind, thus increasing its resulting velocity. If the plane is traveling at a velocity of 100 km/hr with respect to the air, and if the wind...

1. Problem Statement: What is the velocity of John relative the bus in each of the following situations: A) John is sitting on the street and the bus is moving at 30m/s toward him B)John is sitting in his car traveling North at 25m/s toward a stationary bus? C)John is sitting in his car...

A police car is chasing a stolen car ahead of it. If the police car is traveling at 150 km/h (N) and the stolen car is traveling at 120 km/h (N), then determine: a) velocity of police car relative to ground b) vel. to the pol. car relative to the stol. car c) vel of stol car relative to the pol...

While traveling on a train, two boys play catch in the aisle. The train is moving north at 30.0 m/s. The ball is tossed front to back at 5.0 m/s relative to the boys. A bystander on the highway observes the ball being tossed toward the back. To the bystander, what is the relative speed of the...

Mostly for self interest: If I drop a 1lb weight from 15 ft (5m), what does it weigh when it hits the floor. If I have a 10lb weight and it drops from the same 5m shelf, does it weigh 10 times as much as my 1 lb weight from the 1st question? I may have the wrong terminology, but basically the...

How can we show one dimensional relative parallel velocities in space time diagram ? (One dimensional means there's only pozitive and negaive values of speed)

Hello! This is my first post, so I should make a small introduction. I am not a science expert in anyway shape or form, but I am a keen enthusiast who regularly keeps up to date with science news through popular websites such as IFLS, Space, BBC etc. I have been wondering about this particular...

Homework Statement An elevator is going up from the ground with acceleration aelevator/ground. When the elevator's height measured from the ground is h, its velocity us velevator/ground (assume that t = 0 in this condition), a ball is thrown up with velocity vball/elevator relative to the...

According to page 61 'Einstein' by Andrew Robinson an electric charge at rest produces no magnetic field. But: For an observer moving East with uniform motion the charge will appear to be moving West uniformly and B, using a sensitive compass, will detect a magnetic field around the 'moving'...

Lets suppose we have a observer O and two objects A and B a speed is 0.5c and B speed is 0.3c than we can calculate other relative speed acoording to these informations.We know that (according this info B sees A going to 4/17c but we can pretty sure that's true because we can't ask. him How...

1. I'm a middle school science teacher with no science background, and I'm trying to avoid teaching any misconceptions on this topic! However, I don't know that I grasp what's going on here myself. I'm trying to explain rationale for why, on a circuit diagram, the symbol for a resistor may...

Homework Statement A freight train is moving at a constant speed of 10 m/s. A man standing on a flatcar throws a ball into the air and catches it as it falls. Relative to the flatcar, the initial vellocity of the ball is 15 m/s straight up. a. What are the magnitude and direction of the...

Lets suppose three objects O,A and B are set up in universe and nothing else.Then O seems A is moving 0.3c And B is moving 0.5c .In Special Relativity we have relative velocities formula I want to formule it but result seems absurd can you find me all possible velocities I mean A, O and B...