## ASVAB Mechanical Comprehension Principles Practice Test 364862

 Questions 5 Focus Principles Topics Inertia, Mechanics, Newton's Second Law of Motion, Universal Gravitation, Weight Question Type Questions

#### Study Guide

###### Inertia

The more mass a substance has the more force is required to move it or to change its direction. This resistance to changes in direction is known as inertia.

###### Mechanics

Mechanics deals with motion and the forces that produce motion.

###### Newton's Second Law of Motion

Newton's Second Law of Motion states that "The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object." This Law describes the linear relationship between mass and acceleration when it comes to force and leads to the formula F = ma or force equals mass multiplied by rate of acceleration.

###### Universal Gravitation

Newton's Law of Univeral Gravitation defines the general formula for the attraction of gravity between two objects: $$\vec{F_{g}} = { Gm_{1}m_{2} \over r^2}$$ . In the specific case of an object falling toward Earth, the acceleration due to gravity (g) is approximately 9.8 m/s2.

###### Weight

Mass is an intrinsic property of matter and does not vary. Weight is the force exerted on the mass of an object due to gravity and a specific case of Newton's Second Law of Motion. Replace force with weight and acceleration with acceleration due to gravity on Earth (g) and the result is the formula for weight: W = mg or, substituting for g, weight equals mass multiplied by 9.8 m/s2.