ASVAB Mechanical Comprehension Practice Test 640552

Questions 5
Topics Joules, Newton's Second Law of Motion, Normal Force vs. Weight, Types of Simple Machines, Work

Study Guide

Joules

The Joule (J) is the standard unit of energy and has the unit \({kg \times m^2} \over s^2\).

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.

Normal Force vs. Weight

Normal force arises on a flat horizontal surface in response to an object's weight pressing it down. Consequently, normal force is generally equal to the object's weight.

Types of Simple Machines

The six types of simple machines are the lever, wheel and axle, pulley, inclined plane, wedge, and screw.

Work

Work is accomplished when force is applied to an object: W = Fd where F is force in newtons (N) and d is distance in meters (m). Thus, the more force that must be applied to move an object, the more work is done and the farther an object is moved by exerting force, the more work is done.