Gravity is one of the fundamental laws of the physical universe. It is an important concept that must be understood in order to respond to many mechanical aptitude questions. While a full discussion of gravity is beyond the scope of this guide, for the purpose of answering mechanical aptitude questions, you only need to know a few key facts.

Key Facts

·         Essentially, gravity is the constant downward force that keeps people and objects on the Earth.

·         The force of gravity is such that it will create resistance for any other force or effort that tries to elevate an object above a resting point.

·         In general, the force of gravity exerted upon every object is the same, regardless of the object’s weight, size, shape, etc. Thus, objects moving only by the force of gravity (i.e., in free fall) will move at the same rate toward a resting point.

Mechanical aptitude questions related to gravity often involve falling objects, swinging pendulums, structural support components, etc. In this section, we will present example questions involving objects in motion and objects not in motion.

The answer is B. Because gravity always pulls objects downward, the ball at the end of the rope would be drawn straight down toward the ground. Hence, in the absence of some other force, such as a magnetic force, it is unlikely the ball would be suspended as presented in Situation B.

Gravity Summary

Typical mechanical aptitude tests do not ask questions about gravity in textbook form (e.g., “What is an object’s rate of descent?”). Instead, they ask you to apply your understanding of how gravity operates in given situations (e.g., “Which of these two objects will hit the ground first?”). The information presented in this section – together with what you probably already know from simply observing your environment – provides a foundation for answering mechanical aptitude questions involving the force of gravity.