Question

Which of the following objects is in equilibrium?

Answer 1

A bicycle sitting on the ground is the statement that suits best to describe the objects in the equilibrium.

Answer: Option B

Explanation:

Equilibrium refers to the static state when there is no movement or displacement. In other words it also means that the forces acting on the object are equal and opposite in direction and the net force will be zero as they are in opposite direction and hence the object doesn't move and remains in the static position. The options A,C,D are related to movement of the object.

Answer 2

b- a bicycle sitting on the ground

a- a car moving at a constant velocity  

An object is in equilibrium when the forces acting on the object are opposite of one another and equal. In this case, the force of the ground and the force of gravity are both acting on the object, but since the object either isn't moving or has constant velocity, the forces are therefore equal and in opposite directions.