Suppose three identical steel balls Q, R, and S, are placed on an undulating ground as illustrated in the diagram above. Which of the balls is/are in neutral equilibrium?
Attached Figure / Diagram
A
S only
B
Q only
C
R only
D
Q and S only
Verified Correct Answer: C.
Physical Principles & Numerical Solution
A body is in neutral equilibrium when, upon receiving a slight displacement, it tends to come to rest in its new position, e.g., a ball rolling on a horizontal surface, or a cone resting on its curved surface.
Ball R: Positioned in a trough between two crests. If displaced slightly, it will move to a new position and remain there, showing it is in neutral equilibrium
Source: WAEC / JAMB / NECO Classroom Archive (Record #63072)