Relative Definition and 1000 Threads

"everything is relative" hy guys,so Einstein jad a quote "everything is relative" but he proved that lightspeed has speed c relative to any reference frame ,doesn t that means that c is absolute? hope i made myself clear.

Homework Statement Air/Water vapor mixture, at 26C and 45%RH. What is the Dew-point temperature Homework Equations Tdp = Tsat when pg=pv RH = pv/pg The Attempt at a Solution From the psychrometric chart I can get the Humidity ratio, volume per kg dry air, Enthalpy, and...

Homework Statement Hey guys, I've attached the question. Homework Equations The Attempt at a Solution m=3000kg s=75m F thrust = 22000 N v_plane = v_carrier + v_plane/carrier v_plane = v_carrier + (240/3.6) not sure where to go with forces...

Its known that the speed of light is constant...(if you emit a light Eastward while your physically traveling East c will still be the same as if you were still) but also, through an experiment i am imagining, the speed of matter should be relative as well...(if your traveling Eastward and you...

Homework Statement I am working on a simulated lab in which we have a single particle projectile launched at a target particle (located at the center of the circular chamber) of similar weight. Once the collision takes place, I record the time it takes for the scattered projectile to travel...

does inflation affect time? my question arises from @ ~7:30min. if space itself can be used as a reference point for speed, is it an omnipresent observer? is it therefore not excepted from SR if space is moving relative to space? I have searched the forums already, I am trying not to...

Homework Statement A wheel with a radius 50 cm is rolling along the ground at 10m/s[E]. That is, the centre point of the wheel is moving at 10 m/s [E]. - What are the velocities of the top, bottom, front, and back points of the wheel, relative to its center? - What are the velocities...

Hi, This week I was in an accident - one track road head on round a bend. My impression was that the other car was faster and yet their car was more damaged. I know that make and design is a huge issue in this but trying to recall my physics and failing. In the not real, frictonless...

Say I am at point X. My friend, Gary, is 20m from X, and my friend Liam is 40m from X. Gary is traveling at 5 metres per second in a circle around me, remaining 20m from X. What speed must Liam travel at to appear, to me, to be traveling at the same speed as Gary? Is it 10 metres per second or...

Is it possible that a particle traveling so close to c from its reference frame observes objects within their schwarzschild radius? In other words is it possible that in these particles reference frames is a universe primarily comprised of black holes? If so then would gravity be relative?

Hi English is not my native language and I have these type of questions all the time. I would like to know if the terms Linked and Opposed are correct when one wants to talk about the position of two vertices relative to a quad for example, as in: "Vertices A and C have an Opposed Relation."...

Homework Statement A plane must fly to a destination located due north from its departure point. A gentle wind is blowing from the south-west. What direction must the plane point to reach its destination? Homework Equations The Attempt at a Solution...

Now, I know that tittle is messy, so I'm going to explain it as clearly I can. One of the proofs to the fact that time is relative is, as I've heard. Putting one clock on the ground, and another a few feets above it. When these clocks measure time, the one above the ground will do it faster...

As I understand it, the universe is approx. 14 billion years old. Light from the farthest observed galaxies took several million or billion years to reach us. Now my question is: If it takes for example, 500 million years for light from a certain galaxy to reach us it is 500 million light years...

Homework Statement Calculate the time taken for particle A to catch up with particle B. See attachment for variables. I worked out the answer by finding the relative velocity of A wrt B but apparently there's another method I should have/could have used to solve it? Homework Equations...

Does kinetic energy of a body contribute to the stress-energy tensor of a black hole. If I move with respect to a black hole I would perceive it to have more energy. So would it have a stronger G field in my frame. Would it have a larger Schwarzschild radius. My assumptions are probably...

Homework Statement A river is flowing 4.0 m/s to the east. A boater on the south shore plans to reach a dock on the north shore 30.0 Degrees downriver by heading directly across the river. What should be the boat's speed relative to the water? Also, what's the boat's speed relative to the...

The image shows four points. "A" is source of light and "B" is receiver, and "a" and "b" represents co-ordinate points. "A" is moving with constant speed to "B". "B" feels doppler effect. If "B" moving with constant speed to "A", then also "B" feels doppler effect. Statement 1: This two...

Homework Statement A long-distance swimmer is able to swim through still water at 4 km/h. She wishes to try to swim from Port Angeles, WA, due north to Victoria, B.C., a distance of 50 km. An ocean current flows through the Strait of Juan de Fuca from west to east at 3 km/h. In what...

I'm new to the forum and physics in general so forgive the stupidity. I was wonderings if, hypothetically, if one had a 'straight' rod 1000 miles long and balances it horizontal to the earth, would the rod be 'straight [i.e. I shape] or curved [i.e. ( shape]. What I mean is: Is what I consider...

My understanding of relativity is that if two masses are in constant motion relative to each other, either one of them could be considered at rest with the other moving and it makes no difference which. However thinking about a collision between a big truck and a small car makes me wonder about...

Imagine a car moving at fixed speed relative to the pavement of a street. I understand that from the point of view of the observer on the pavement, the car is moving. But from the point of view of the observer in the car, the pavement id moving. But how could this be? How could the pavement be...

It was only in 2004 with the launch of Gravity Probe B that spacetime curvature was physically ascertained to exist, previous to that, it was a simply an extremely elegant proposition underlying GR. Similarly, has the increase of mass with relative velocity been physically proven to exist or...

Homework Statement Problem-5: In the class we saw that property of additivity of the entropy for systems in thermalcontact relies on the approximation that we compute entropy of the most probable state ln(g1g2)maxinstead of full ln g(N,U) = ln(P,U1) g(N1,U1)g(N2,U −U1)). The error made turns...

Homework Statement Anyone mind checking my answer for me? The area of a right triangle with hypotenuse H is A=1/4H^2sin(2x) x is one of the acute angles. Use differentials to estimate the relative errors of the area if H = 4cm exactly and x is measured to be 30degrees with an error of...

The problem A bubble of kryptopn (Kr) gas is formed underwater. The bubble has a volume of 2.14x10-6m3 and contains 1.70x1020 krypton molecules each of mass 1.39x10-25kg. The pressure of the gas inside the bubble is 300kPa. Calculate the relative molecular mass.The attempt at a solution When...

Does the relative motion of a thing slow down the relative motion of a thing? Hope that makes sense or you can work out what I mean.

Hi, just a small doubt I'm having: I'm given a cross tabulation table, such as undernourished status versus gender of the child: -----------------------------undernourished -----------------------------yes--------no --------------------boy------37-------- 86 ---------gender...

People always say the Universe is 14 billions year old. But what does that mean? What is the time of the Universe relative to?

Homework Statement A smooth wedge of mass 2m and slope 45 degrees is placed on a smooth horizontal surface. A particle of mass m is placed on the inclined face of the wedge. The system is released from rest. (i) Show on separate diagrams the forces acting...

Galileo's pendulum could have shown that local time is relative Making experiments with pendulums Galileo discovered the following properties: - Pendulums nearly return to their release heights. - All pendulums eventually come to rest with the lighter ones coming to rest faster. -...

I have a couple questions about relative motion, since I've been reading everywhere that motion is relative... (Feel free to point me to other threads that answer these questions if there are any - I searched and couldn't easily find any) QUESTION #1 So if I'm standing still, and...

Homework Statement What is the easiest way of finding the symmetrical of a point relative to an arbitrary line? (I was asked on an exam to find the symmetrical of a point relative to the line y = x, but that's rather trivial - just switch the coordinates. How can I do it for any arbitrary...

What exactly comprises a relative velocity in special relativity? I find it confusing when distant galaxies can be moving away from the Earth at speeds approaching the speed of light and yet that separation speed contributes nothing to a relative velocity. The usual answer provided is that both...

Edit. I think the topic is misinformative and I don't know how to change it. Hey I have to translate this into english so bear with me. Two spaceships are approaching Earth from two directions along the x-axis. Earth observer(EO) calculates their speeds to be 0,8c each. Calculate at what...

Homework Statement I have a twin brother, and we're 30 years old. If i travel for three years at 2.55 X 10^8m/s (0.85c) while my brother is a rest on Earth, how much older than me will my brother be upon my return?Homework Equations t=To/√1-v^2/c^2 [b]3. Try to work out To=3 T=? V= 2.55 X...

Homework Statement A kayaker needs to paddle north across a 100-m-wide harbor. The tide is going out, creating a tidal current that flows to the east at 2.0 m/s. The kayaker can paddle with a speed of 3.0 m/s. Homework Equations v= v + V Let the Earth frame be S and a frame attached...

Please excuse my ignorance - I am a biologist by training - but this is one of those questions that just keeps bothering me and I can't find the answer with Google/Wikipedia. Take as our example the ocean currents on the Earth caused by the Coriolis Effect of the Earth turning. When I read up...

Hello everyone! I need some help with a Doppler effect/relative motion question. Homework Statement A whistle with a frequency of 1200 Hz is traveling south at a velocity of 30.0 m/s. You are traveling north away from the whistle at a speed if 18.0 m/s. If the speed of sound is 340 m/s, what...

Homework Statement Show that the function f(x) = x\sin\left( \frac{\pi}{x} \right) has an infinite number of relative extrema. Homework Equations The Attempt at a Solution Using the product rule and chain rule to find the derivative f'(x): f'(x) = \sin\left( \frac{\pi}{x} \right) -...

A boat A is chasing boat B along a river by moving in the same direction as the stream. The speed of the river stream is 6 miles per hour, the speed of boat B relative to the river is 48 miles per hour, and boat A is 8 miles per hour slower than boat B. Currently boat B is ahead of boat A...

Homework Statement Let m1, m2 and m3, the mass of 3 particles and v12, v23, v13 their respective relative velocities. a) Show that the total kinetic energy of the system in relation to the center of mass is: ( m1m2v12^2 + m2m3v23^2 + m1m3v13^2 ) / (m1+m2+m3) b) generalize this result...

Hello, Let me first say this is not homework, If you do not believe me you can use any numbers you would like. I am just curious and would like to see how the "speed" of an object changes relative to different things. Basically, if say, I move 10 mph (or 20 mph, or 5 feet a second, it...

Homework Statement Might be the sketch most useful first: The prism is sliding horizontally from left to right under condition : S(t)=4*t*t+5*t+1[cm] and the bar OA is rotating, point A is sliding over the prism's slope and point O is the immobilized center of bar's rotation, OA=10cm...

Greetings, I have a work requirement to calculate building chilled water use based on known supply temp (deg F), return temp (deg F) and flow (GPM). I would like to know the relative error associated with the energy calculation. Based on the product data for the sensing equipment, I know that...

Homework Statement mass of Fuzzy = 100.0kg mass of cart = 200.0kg Homework Equations Conservation of Momentum for 1D Motion Relative Velocity for 1D Motion The Attempt at a Solution Since everything is at rest at the beginning, the total momentum of the system is 0. So at the end, 0 =...

Homework Statement Two people push in opposite directions on a block that sits atop a frictionless surface (The soles of their shoes are glued to the frictionless surface). If the block, originally at rest at point P, moves to the right without rotating and ends up at rest at point Q...

Hi, I've been listening to a Professor Jim Al-Khalil's scipod on time travel. I think this guy is bloody excellent by the way. http://reader.mac.com/mobile/v1/http%3A%2F%2Fwww.jimal-khalili.com%2Fpodcast%2Fjim.rss Anyway, He said to an observer on the Earth a clock on a...

Hi.. What will be the nature of relativistic mass when a body moves with speed of light..?

When one says they are at rest relative to the cosmic microwave background, does this mean that they are in a frame where the same frequency is measureed in all directions? Because, I could imagine if I boosted in one direction, then the spectrum behind me would be redshifted, and the spectrum...