# Will a pendulum oscillate on the ISS?

A question I encountered is whether a pendulum undergoing SHM on earth will oscillate on the ISS. Apparently the answer is it won't due to no effective gravity. The argument is there will be no tension force as all of it is on free fall. How is this different to on earth, where the entire setup is acted upon by g.

The ISS and everything in it including your pendulum, is in low orbit around the earth. Its acceleration towards the earth is close to $$9.8\,m/s^2$$ which is the value on the earth's surface. There is no other significant force acting on the ISS (or our pendulum) so it's in free fall.