Sanjay hangs upside down from a tree branch. He has a pencil tucked behind his ear. What happens to the pencil when Sanjay is upside down?

Respond very briefly.
When Sanjay is upside down, the pencil will fall to the ground. Gravity acts downwards towards the center of the Earth, so when Sanjay is upside down, there is no longer any support against gravity to hold the pencil behind his ear. Since his head is inverted, what was once the top where the pencil rested is now beneath the pencil, and there is nothing to keep the pencil in place. Thus, the pencil is pulled by gravity and drops to the ground.