Final answer:
The sum of forces in the y direction will be 0 when the object is in equilibrium or at rest.
Step-by-step explanation:
The sum of forces in the y direction will be 0 when the object is in equilibrium or at rest.
In equilibrium, the forces acting in the y direction will cancel each other out, resulting in a net force of 0. This means that the forces upward and downward will have equal magnitudes.
For example, if an object is placed on a table, the force of gravity pulling it downward is balanced by the normal force exerted by the table pushing it upward, resulting in a net force of 0 in the y direction.