Speed relativity, Einsteins theorie

Thread starter slrn
Start date Nov 10, 2012
Tags

Relativity Speed

AI Thread Summary

To determine the speed required for an astronaut to reach a solar system 80 light-years away in 8 years, the Lorentz contraction formula is applied. The proper length (L0) is 80 light-years, and the time experienced by the astronaut (T0) is 8 years. By rearranging the equations, the speed can be expressed as a function of distance and time. The calculations involve solving for velocity (v) using the relationship between proper length and time dilation due to relativistic effects. Ultimately, the astronaut must travel at a significant fraction of the speed of light to achieve this journey within the specified timeframe.

Nov 10, 2012

slrn

Homework Statement

astronaut has 8 years to get to a solar system that earthlings see is 80c years from earth. How fast does the astronaut have to go to get there in 8 years.

Homework Equations

L=L0(sqrt(1-(v/c)^2)
L0/T=L/T0

The Attempt at a Solution

L0 = 80 cyears
T0 =8 years

Physics news on Phys.org

Nov 10, 2012

Doc Al

Mentor

Hint: Express the speed in terms of distance and time.

Thread 'I've come across another fluid pressure problem I don't understand'

Neglect gravity other than that of water; neglect friction. F1=ρgsh=1000*10*1*(1+4)=50000 N; F1=ρgsh=1000*10*0.1*4=4000 N; F3=50000-4000=46000 N?

View full post »

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...

View full post »

Thread 'Egg Drop Challenge! Need ideas for winning designs'

I was thinking using 2 purple mattress samples, and taping them together, I do want other ideas though, the main guidelines are; Must have a volume LESS than 1600 cubic centimeters, and CAN'T exceed 25 cm in ANY direction. Must be LESS than 1 kg. NO parachutes. NO glue or Tape can touch the egg. MUST be able to take egg out in less than 1 minute. Grade A large eggs will be used.

View full post »