ASVAB Mechanical Comprehension Practice Test 300661

Questions 5
Topics Coefficient of Friction, Joules, Specific Gravity, Types of Simple Machines, Work

Study Guide

Coefficient of Friction

Coefficient of friction (μ) represents how much two materials resist sliding across each other. Smooth surfaces like ice have low coefficients of friction while rough surfaces like concrete have high μ.

Joules

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

Specific Gravity

Specific gravity is the ratio of the density of equal volumes of a substance and water and is measured by a hyrdometer.

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.