1. The problem statement, all variables and given/known data A.P. French q.no. 4.3 2. Relevant equations t = L\c, (1) L0 = ϒ L 3. The attempt at a solution The observer's frame is that frame w.r.t. which the meter stick is moving with speed 0.8c. The observer sees the mid-point at (x,y) at a time to(measured from the clock situated at the observer's position) while mid-point passes the point (x,y) at time t [measured from the clock kept at (x,y)] . And it is assumed that all clocks are synchronized. Now , to = (√(x2+y2) )/c + t, (3) x = vt, v = 0.8 c At to =0, t = - (√(x2+y2) )/c, note that t is negative here. c2t2 = v2t2 + y2 t2 = 1/(1-0.64)c, t =- 1/(0.6c) So, At to =0, x= -4/3 m, y =0m now, length of the meter-stick is L = 1(√(1-0.64)) m = 0.6 m So, the left end will be at - (0.3+4/3)m and the right end will be -(4/3-0.3) at y=0. Is this correct? B) The observer sees the mid-point at to= 1/c s. C)To the observer the end points appear at 0.3 m left and right to the origin. What do I learn from solving this question? Measurement of position of ends of stick at time t And measurement of the time at which an event happens will be different for observers located at different positions in the same reference frame. Is my learning correct?