# Tension in a string in free fall

A body is attached to another with a string and both are in free fall. How does the tension in the string being zero make sense conceptually?

• This question would become much more answerable if you told us why you think it doesn't make sense. – ACuriousMind Mar 22 at 18:56
• Draw a free body diagram (including a tension force) for each mass and write N2L equations. If they are in free fall, you know they have the same acceleration, and it is $\vec{g}$. If there is tension which isn't zero, they can't have that acceleration. – Bill N Mar 22 at 19:09
• because if you hold one body in your hands at the ground level - string will experience tension because other body will affect string with weight. And when on free fall both bodies have zero weight, thus - no force is applied to a string, and that's why you will get no tension. – Agnius Vasiliauskas Mar 22 at 20:10

Now imagine two objects attached by a string one vertically above the other with the string stretched out in free fall. The distance between the objects is constant. Now imagine you are also in free fall between the two objects. You cut the string. Will the distance between the two objects increase like in the tug of war? No, the separation will remain the same because the acceleration of each object, $$g$$, will remain the same. Conclusion: there was no tension in the rope.