Question

Russ makes the diagram below to organize his notes about how Newton’s first law describes objects at equilibrium.



Which label belongs in the region marked X?

Has a net force of zero
Has a velocity of zero
Is moving with a constant velocity
Is slowing down and coming to rest

Answer 1

Newton's first law states that an object at rest remains so until acted upon by external forces or an object in motion does so without accelerating (that is, at constant speed).

Therefore, x can only describe an object coming to rest. That, the last option is more correct.

Answer 2

Correct options:

Has a net force of zero

Explanation:

Newton's first law, also known as law of inertia, states that:

"An object at rest which has a net force of zero acting on it stays at rest, and an object moving at constant velocity which has a net force of zero acting on it continues its motion at constant velocity"

The first situation (object at rest) is called static equilibrium, while the second situation (object moving at constant velocity) is called dynamic equilibrium. As we read from the statement of the Newton's first law, in both situations the object has a net force of zero acting on it, so this is the label that should be placed in region X (which is the region in common between both dynamic and static equilibrium)