The speed of sound depends on the medium that the waves pass through, and is a fundamental property of the material. The first significant effort towards the measure of the speed of sound was made by Newton.
When the Occupational Safety and Health Act passed in 1970, steel-toe boots became a standard in the American workplace, preventing thousands of on-the-job injuries. Today's technology has only increased the variety of work boots available, and it's important to understand the differences before purchasing a pair.
An average boot of any type will have a calf size anywhere from 14-15 inches in circumference leaving many plus sized and athletic women with wide calves out of luck. Understanding the needs of different women, however, many shoe designers have begun to offer boots with wide calves which can range in size from 16 to 20 inches.