## ASVAB Mechanical Comprehension General Practice Test 152756

 Questions 5 Focus General Topics Bridge Forms, Ceramics, Force Lines of Action, Modulus of Elasticity, Specific Gravity Question Type Questions

#### Study Guide

###### Bridge Forms

The six basic bridge forms are beam, truss, arch, cantilever, cable, and suspension.

###### Ceramics

Ceramics are mixtures of metallic and nonmetallic elements that withstand exteme thermal, chemical, and pressure environments. They have a high melting point, low corrosive action, and are chemically stable. Examples include rock, sand, clay, glass, brick, and porcelain.

###### Force Lines of Action

Collinear forces act along the same line of action, concurrent forces pass through a common point and coplanar forces act in a common plane.

###### Modulus of Elasticity

The modulus of elasticity measures how much a material or structure will deflect under stress. Stretch modulus is longitudinal stretch (like stretching raw bread dough), shear modulus is longitudinal deflection (like the horizontal displacement of a stack of magzines when a heavy object is placed upon them), and bulk modulus is compression of volume (like the compression of a loaf of bread under a heavy can at the bottom of a grocery bag).

###### Specific Gravity

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