Question

a pendulum clock is thrown out of an aeroplane how will it behave during its free fall in air​

Answer 1

Answer:

 The pendulum  will continue to move it's angular motion without any change in its angular speed -so the angular momentum- with respect to freely falling lift. At this point (start of free falling) there is no gravity force felt inside the lift. So you can imagine it like a room in space where there is no gravity

Answer 2

Explanation:

Gravitational acceleration decrease with altitude.