A measuring stick placed along the circumference of a rotating disk will appear contracted, but if it is oriented along a radius, it will not. Explain.
Solution 23RQ The stick will appear contracted as the circumference of the disk will have length contraction when the disk is rotating. But the radius being perpendicular to the direction of motion (rotation) will not have any such contraction in length. So, no contraction if the stick is observed is oriented along the radius.