ASVAB Mechanical Comprehension Practice Test 592577

Questions 5
Topics Joules, Normal Force, Wedge, Wheel and Axle

Study Guide

Joules

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

Normal Force

Normal force (FN) represents the force a surface exerts when an object presses against it.

Wedge

The wedge is a moving inclined plane that is used to lift, hold, or break apart an object. A wedge converts force applied to its blunt end into force perpendicular to its inclined surface. In contrast to a stationary plane where force is applied to the object being moved, with a wedge the object is stationary and the force is being applied to the plane. Examples of a wedge include knives and chisels.

Wheel and Axle

A wheel and axle uses two different diameter wheels mounted to a connecting axle. Force is applied to the larger wheel and large movements of this wheel result in small movements in the smaller wheel. Because a larger movement distance is being translated to a smaller distance, force is increased with a mechanical advantage equal to the ratio of the diameters of the wheels. An example of a wheel and axle is the steering wheel of a car.