ASVAB Mechanical Comprehension Practice Test 173747

Questions 5
Topics Bridge Forms, Gravitational Potential Energy, Inclined Plane, Structural Loads, Types of Simple Machines

Study Guide

Bridge Forms

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

Gravitational Potential Energy

Gravitational potential energy is energy by virtue of gravity. The higher an object is raised above a surface the greater the distance it must fall to reach that surface and the more velocity it will build as it falls. For gravitational potential energy, PE = mgh where m is mass (kilograms), h is height (meters), and g is acceleration due to gravity which is a constant (9.8 m/s2).

Inclined Plane

An inclined plane is a simple machine that reduces the force needed to raise an object to a certain height. Work equals force x distance and, by increasing the distance that the object travels, an inclined plane reduces the force necessary to raise it to a particular height. In this case, the mechanical advantage is to make the task easier. An example of an inclined plane is a ramp.

Structural Loads

A concentrated load acts on a relatively small area of a structure, a static uniformly distributed load doesn't create specific stress points or vary with time, a dynamic load varies with time or affects a structure that experiences a high degree of movement, an impact load is sudden and for a relatively short duration and a non-uniformly distributed load creates different stresses at different locations on a structure.

Types of Simple Machines

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