Answer:
What time of day, when written in capital letters, is the same forwards, backwards, and upside down?
What is as light as a feather, but not even the strongest man on earth can't hold it for more than 1 c)minute?
What is the center of gravity?
What has no hands but might knock on your door, and if it does you better open up?
It goes up and down the stairs without moving.
I can only be played on a windy day