Question

When an elevator cabin comes down, the cabin and all the bodies fixed in
the cabin are accelerated with respect to​

Answer 1

When an elevator cabin comes down, the cabin and all the bodies fixed in the cabin are accelerated with respect to the man standing on the earth.

The elevator cabin is coming down and because of this, all the bodies will experience a downward force, hence the elevator cabin is a non-inertial frame.

But a person standing on the ground is in an inertial frame that is the non-accelerated frame.

Hence the elevator cabin will seem to be accelerated with respect to the man standing on earth.