Relativity Question (1 Viewer)

kurt.physics

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This isnt a question from a text or anything but im just curious.

A man, man A, is in a rocket travelling at 99% (<-- just arbitrary) the speed of light. He turns on a 100W lamp for 1 hour exactly (by his watch). Later his electricity company rang him and claimed he had a $1000 bill for using the lamp. He said that he only had it on for an hour, this is rediculous! So he quickly calculated how much it would cost him for 1 hour with it on (using what ever formula it is...but i know it has time in it) and said i only need to pay $1.

How much does he have to pay, $1000 or $1?
 

shaon0

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I think you can...
((Speed of light-99% of speed of light) /Energy)*1 hour
 
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Aerath

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Depends on whether or not you're from the perspective of the man or the electricity company, right? That changes the to and/or the tv (I think).
 

kurt.physics

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Aerath said:
Depends on whether or not you're from the perspective of the man or the electricity company, right? That changes the to and/or the tv (I think).
This is what i think also, but what does he have to pay? <-- not the exact amount but who is right, him or the company?
 

lyounamu

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kurt.physics said:
This isnt a question from a text or anything but im just curious.

A man, man A, is in a rocket travelling at 99% (<-- just arbitrary) the speed of light. He turns on a 100W lamp for 1 hour exactly (by his watch). Later his electricity company rang him and claimed he had a $1000 bill for using the lamp. He said that he only had it on for an hour, this is rediculous! So he quickly calculated how much it would cost him for 1 hour with it on (using what ever formula it is...but i know it has time in it) and said i only need to pay $1.

How much does he have to pay, $1000 or $1?
If he didn't use that much, he should pay 1 dollar. I don't really get the question. Does the amount of electricity increase if you travel at fast speed?

Damn, I hate physics.
 

Aplus

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As an object approaches the speed of light, the mass of that object will increase due to the need to increased force to allow for increased acceleration. Since energy is proportional to mass, the mass that the object gains should be equal to the electricity that it loses. This follows the Law of Conservation of Energy that, "Energy can not be created nor destroyed, but merely transformed from one form to another." Basically, the electricity (potential energy) has been converted into mass, which allows the object to increase its acceleration towards the speed of light (kinetic energy). As the electricity is lost to mass, the consumption of energy would decrease. Therefore, although the same amount of energy would remain present in the mass of the object, the object would not actually be using energy in the form of electricity. Therefore, he would only be paying $1.
 
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Aerath

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Aplus said:
As an object approaches the speed of light, the mass of that object will increase due to the need to increased force to allow for increased acceleration. Since energy is proportional to mass, the mass that the object gains should be equal to the electricity that it loses. This follows the Law of Conservation of Energy that, "Energy can not be created nor destroyed, but merely transformed from one form to another." Basically, the electricity (potential energy) has been converted into mass, which allows the object to increase its acceleration towards the speed of light (kinetic energy). As the electricity is lost to mass, the consumption of energy would decrease. Therefore, although the same amount of energy would remain present in the mass of the object, the object would not actually be using energy in the form of electricity. Therefore, he would only be paying $1.
I'm sure the electricity company disagrees.
 

Aerath

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lyounamu said:
If he didn't use that much, he should pay 1 dollar. I don't really get the question. Does the amount of electricity increase if you travel at fast speed?
Not really. Time, mass and speed change, though, due to a dilation factor.
 

Aerath

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LOL, hahaha. But yeah, as someone else mentioned, the OP's thought experiment has a whole heap of loopholes in it. :p
 

Steth0scope

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It can be either depending on the frame of reference. Neither frame of reference is preferred over the other (as Newton quite rightly put it).
 

dwarven

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the electricity company would've recorded the person as having the lamp on for 7 hours.

so im saying $1

[and well YOU only used the lamp for an hour, stuff them and their slow frame of referance]
 

Riet

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The correct answer is it depends where the meter is. If it's on his spaceship (like it is on your house), then it will only record 0.1 kW/h.
 

qmaz

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he has to pay $1001 because he cant get his shit together and decide whether he wants to travel at the same speed as a normal human
or be a cunt and travel at 0.99c
 

dwarven

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but leaving a light on for 7 hrs doesnt cost 1k
 

lyounamu

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qmaz said:
he has to pay $1001 because he cant get his shit together and decide whether he wants to travel at the same speed as a normal human
or be a cunt and travel at 0.99c
LOL
 

lionking1191

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it's not a valid example

your thought experiment is based on the assumption that the site of production of energy is in a different frame of reference which is travelling at relativistic speeds in relation to the site of consumption of energy.

there is no plausible way in which that assumption stands in the described scenario, so, try again.
 

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