4. (10 marks) A rectangle is moving along its diagonal. How does its area A vary with speed '0? 5. (20 marks) If a rectangle of size 1m x x/gm is moving along its diagonal, in what speed that it will appear as a square, if possible? 6. (20 marks) Assume that Newtonian concept of space and time was correct and the speed of light in ether was c. We set up a mirror with distance L from us. (a) What would be the time taken for a light pulse to travel to the mirror and reected back, if everything was at rest relative to ether? (b) What would be the time taken if the whole setup was moving with velocity v (as a vector) relative to ether