Relativity questions (1 Viewer)

[M@ster P]

Hi guys i need help with these questions:

• If our galaxy, the milky way is 65000 light years in radius, calculate how fast a spacecraft would need to travel so that its occupants could travel right across it in 45 years.

2. The length of a space craft is observed, by someone on a nearby planet, to shrink to half its proper length. Calculate:
a)[FONT=&quot] [/FONT]the speed of the spacecraft relative to the planet

b)[FONT=&quot] [/FONT]the observed mass of the spacecraft if its rest mass is 5x 10^4kg.


c)[FONT=&quot] [/FONT]the amount of time passed on the planet when one second has passed on the space craft, as observed from the planet.




3. A martian spaceship travelling at near light speed passes a stationary Venusian spaceship. Each is made of glass and in each the occupants are holding a dance party.
(a). Describe the dancing Venusians as seen by the Martians.
(b). Describe the dancing Martians as seen by the Venusians.
(c). Are your answers to (a) and (b) contradictory? Explain
















sorry about the fonts guys.

thanks to any1 who helps me

 

[PrettyVacant]

I left out units and all the calculations because I think it'd ruin the fun for you.


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Q:If our galaxy, the milky way is 65000 light years in radius, calculate how fast a spacecraft would need to travel so that its occupants could travel right across it in 45 years.
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-double the radius, 65000x2 => 130000
-130000 light yrs to travel in 45 yrs...just use the speed=distance/time..convert units to ms^-1.

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2nd question: use the lorentz transformations that are on every single physics data sheet, write down the variables you have and then substitute into the equations and manipulate (basic algebra skills, come on) leaving the quantity you wish to determine on one side. You need the mass+time equations for this question.

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3rd question:
This is testing a basic syllabus dotpoint. Relative to the martians the venusians are moving really slowly and vice versa...though nobody is 'Right' or 'wrong'.