class08 - Announcements Reading for Monday: Chapter...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Announcements • Reading for Monday: Chapter 2.6-2.11 • First Mid-term is in 11 days (Feb. 9 th , Review: Lorentz & velocity transformations (relativistic version of Galileo) Transformations (in 1D) If S’ is moving with speed v in the positive x direction relative to S, then the coordinates of the same event in the two frames are related by: Galilean transformation (classical) Lorentz transformation (relativistic) Note: This assumes (0,0,0,0) is the same event in both frames. vt x x = ) ( vt x x = γ ) ( 2 x c v t t = 2 / 1 c uv v u u = v u u = t t = Some examples Suppose a spacecraft travels at speed v=0.5c relative to 2 / 1 c uv v u u = 2 / 1 c v u v u u + + = 2 2 / 1 ' ) ( ) ( c uv v u u x c v t t vt x x = = = Relativistic transformations Q1 the Earth. It launches a missile at speed 0.5c relative to the spacecraft in its direction of motion. How fast is the missile moving relative to Earth? (Hint: Remember which coordinates are the primed ones. And: Does your answer make sense?) a) 0.8 c b) 0.5 c c) c d) 0.25 c e) 0 Velocity transformation: Which coordinates are primed? y y' (x,y,z,t u u is what we were looking for! (i.e. velocity measured in S) S x z S' x' z' v (x,y,z,t) (x',y',z',t') Spacecraft Earth
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
The “object” could be light, too! Suppose a spacecraft travels at speed v=0.5c relative to 2 / 1 c uv v u u = 2 / 1 c v u v u u + + = Q2 Suppose a spacecraft travels at speed v=0.5c relative to the Earth. It shoots a beam of light out in its direction of motion. How fast is the light moving relative to the Earth? (Get your answer using the formula). a) 1.5c b) 0.5 c c) c d) d e) e George has a set of synchronized clocks in reference frame S, as shown. Lucy is moving to the right past ... -3 -2 -1 0 1 2 3 ... v ? George Lucy ) ( ) ( 2 x c v t t vt x x = = γ Q3 George, and has (naturally) her own set of synchronized clocks. Lucy passes George at the event (0,0) in both frames. An observer in George’s frame checks the clock
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 08/24/2010 for the course PHYS 2130 taught by Professor Staff during the Spring '08 term at Colorado.

Page1 / 6

class08 - Announcements Reading for Monday: Chapter...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online