This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: 1.(a) Flashlight and mirror are at rest with respect to spaceship so all times,lengths measured are proper times,lengths. so time in secs measured on spaceship = Lp/c = 300/(3.10 8 ) = 106 s. (b) similarly this time is 2Lp/c = 2. 106 s. (c) and (d) Suppose observer on ground sees the light (traveling at speed c) catch up with the front of the ship (moving at speed v) in time t 1 Then ct 1 = Lp + vt 1 , where Lp =(1/ ) Lp is the length of the spaceship as measured by him. This gives t 1 = (1/ )Lp/(cv)= L p c 1 v 2 / c 2 / (1 v / c ) ( L p c ) ! v / c 1 v / c Now suppose he sees the reflected light take a time t 2 to reach the back of the ship again which has moved forward a distance vt 2 in that time so it has only to go a distance Lp  vt 2 (at velocity c) so ct 2 = Lp  vt 2 giving t 2 L p / ( c v ) ( L p / c ) 1 v 2 / c 2 / (1 v / c ) ( L p / c ) 1 v / c 1 v / c so time he sees for light to get back to flashlight is...
View
Full
Document
 Spring '08
 Hirsch
 Physics, Light

Click to edit the document details