Question

A cone resting on its side is an example of neutral equilibrium.
A. True
B. False

Answer 1

Hint:Recall the concept of equilibrium position of an object. Using this definition then explain the concept of an object in neutral equilibrium. Hence, first check whether the cone is in equilibrium in its rest position on the horizontal surface. Then check whether the cone attains equilibrium when it is slightly displaced from its original position.

Complete answer:
An object is said to be in equilibrium if the net force (sum of all forces acting on the object) acting on the object is zero.An object is said to be in neutral equilibrium if the object is displaced slightly from its initial equilibrium position, the object attains again equilibrium at its new position.For example, an uniform sphere resting on a horizontal surface when displaced slightly from its initial position, it rolls some distance on the horizontal surface and then stops and the net force acting on this sphere again becomes zero.

In the present case, the cone is resting on its one side.The forces acting on this cone resting on its slant slide are the weight of the cone in the vertically downward direction and normal force exerted by the surface on the cone in the vertically upward direction.

The magnitude of this normal force is such that the weight of the cone in the downward direction is balanced. Hence, the net force on the cone is zero. This shows that the cone is in equilibrium.When the cone is displaced slightly from its original position, the cone rolls and again attains equilibrium in its new position where the net force on this cone is zero.This shows that the cone is in neutral equilibrium.

Hence the correct option is A.

Note:The students may get confused between the concepts equilibrium of an object and neutral equilibrium of an object. These two are distinct concepts. The students may also get confused between the concepts stable equilibrium, unstable equilibrium and neutral equilibrium. The students should keep in mind these concepts distinctly.