Question

check each situation where work would occur. you slide a chair across the floor. you hold a tray over your head. you pick up a box. you sit in a chair.

Explanation:

Work in physics is defined as the product of force and displacement in the direction of the force. Sliding a chair involves applying a force to move it (displacement), and picking up a box requires force to change its position (displacement). Holding a tray doesn't cause displacement in the direction of the force applied (just counter - acting gravity), and sitting in a chair doesn't involve force causing displacement related to the action of sitting.

Answer:

You slide a chair across the floor.
You pick up a box.