Imagine two identical rockets in a line with one a distance D behind the other. A flimsy string spans the distance D. Both rockets are initially stationary, and receive a light signal from the midpoint between them that says \"launch.\" The identical rocket engines accelerate both rockets identically up to a speed of 4/5 (in c units). Does the string break? (EDIT: The rockets are in line with each other, one in front and one in back, separated by distance D. Assume they accelerate in the positive x direction.) Solution As we can see here that each and every paramters is same for both rockets. So displacement betweem rocket will not change . So there will be no addition tension genereted. So one basis of that it should not break. But as roket will move from the surafce of any place due do atmospheric friction it will breakdown. .