Question

The leaders of the planet Xanadu have finally decided to launch an invasion of the planet Bilm, 24 light-years away. They simultaneously launch a newly developed missile and a UFO carrying their invasion force. The missile travels at 0.95 c, while the UFO travels at 0.50 c. How much time passes for the invasion force on the UFO between the launch and the detonation of the missile on Bilm’s surface? Assume that Xanadu and Bilm are at rest with respect to each other.

Select one:

a.

22 years (this is the answer but I want to know why)

b.

15 years

c.

13 years

d.

7.9 years

Answer 1

Distance a= 24 ly =24 ly = 24 yn XL = 24C year Speed missile Vi=0.95c of speed of UFO U2 = 0.5 Time to reach the planet Bilm in the rest will be for missile t = 2 = 240 from = 25.3 yr 0.95€ Ufo for tzan als to 24€ = = 48 yr 0.50 Time difference, &t=48-25-3 = 22 yr