Rotational Equilibrium: Balancing a tray with hand and thumb

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You are holding a lunch tray from one end hand holding the tray(four fingers and thumb). Tray has plate and some beverage.
A) what are the forces exerted by your hand on this tray.

For Translational equilibrium of a body net force on the body must be equal to zero. Hence the net force acting on the tray must be equal to zero. The tray will experience a force due to earth's gravity and it is its weight W. To make resultant force on the tray we have to a ...