Bob is on Earth. Anna is on a spacecraft moving away from earth at 0.6 c. At som
ID: 2227750 • Letter: B
Question
Bob is on Earth. Anna is on a spacecraft moving away from earth at 0.6 c. At some point in anna's outward travel, bob fires a projectile loaded with supplies out to Anna's ship. Relative to bob, the projectile moves at 0.8 c. (a) how fast does the projectile move relative to anna? (b) bobo also sends a light signal, how fast does the light signal move relative to anna?Explanation / Answer
a) velocity of Anna relative to Bob = Va-Vb= 0.6c velocity of projectile relative to bob = Vp-Vb = 0.8c => velocity of projectile relative to Anna = Vp-Va = 0.8c - 0.6c = 0.2c Similarly velocity of light with respect to Bob = c => velocity of light with respect to Anna = c - 0.6c = 0.4c