Final answer:
A push stick should be used in woodworking when the material being cut is less than six inches in width. This is for safety to keep hands away from saw blades and cutters. The provided reference information regarding unit scale is used for understanding measurements in blueprints relating to real-world distances.
Step-by-step explanation:
The student's question pertains to the safe operation of woodworking machinery, which is essential to prevent accidents in woodworking shops. A push stick is a safety device used to keep the operator's hands away from the dangerous cutting area of a saw blade or cutter when machining material. The Occupational Safety and Health Administration (OSHA) guidelines suggest that a push stick should be used when the material being cut is less than six inches in width to help maintain a safe distance from the cutting blade.
In the context of the reference information provided, if we consider a unit scale to represent real-life distances, we can deduce that a push stick must be used if the material is less than six inches in width for safety. The unit scale mentioned is likely related to reading blueprints or diagrams where measurements in inches on the document represent feet in real life, as is common in engineering and architectural drawings. For example, the given reference states that to represent a line 500 feet long, the unit scale would be used to draw a line 2(1/2) inches long, which means the scale is 200 feet to 1 inch. Therefore, a line 4 inches long on the drawing would represent an actual line of 800 feet using the same scale.