825.3 consequences of Einstein's postulates Example 1: Sally(at point A)and Sams spaceship (of proper length lo=230 m) pass each other with constant relative speed v Sally measures a time interval of 3. 75 us for the ship to pass her(from the passage of C, what is the relative speed v between Seas of point b to the passage of point C). In term and the ship? Sally B L am 8 25.3 consequences of Einsteins postulates Solution: v=s Loly LoV1-(v/c) Solving this equation for v leads us to L pC v〓 V(c4n)2+L2 230 √(2998×10)(3.57×10)+(230) =0.210c 1919 Example 1: Sally (at point A) and Sam’s spaceship (of proper length L0=230 m) pass each other with constant relative speed v. Sally measures a time interval of 3.75 µs for the ship to pass her (from the passage of point B to the passage of point C). In terms of c, what is the relative speed v between Sally and the ship? §25.3 consequences of Einstein’s postulates Solution: t L v c t L t L v ∆ ∆ γ ∆ 2 0 0 1− ( ) = = = c c t L L c v 0.210 (2.998 10 )(3.57 10 ) (230) 230 ( ) 8 6 2 2 0 2 0 = × × + = + = − ∆ Solving this equation for v leads us to §25.3 consequences of Einstein’s postulates