How does the vertical position of the center of mass affect an object's stability?

• A. Lower center of mass increases stability
• B. Lower center of mass decreases stability
• C. Center of mass position has no effect
• D. Higher center of mass always increases stability

Answer: (A)

The idea being tested is how the height of the center of mass influences stability by determining how gravity’s pull acts as the object tilts. If the center of mass is low, the vertical line of weight stays within the base of support for larger tilts, so gravity creates a restoring moment that nudges the object back toward upright. In other words, a low center of mass keeps the weight’s line of action closer to the center of the base, making tipping less likely. If the center of mass is high, a small tilt shifts the vertical line of weight toward the edge of the base, making tipping more likely because gravity then reinforces the topple. That’s why things with a lower center of mass are more stable.