Final answer:
Manually handled stacks of lumber should not exceed six feet in height for safety. Students calculating how many books they can stack before tipping would need to know the book dimensions and understand the center of gravity principles. Refer to OSHA guidelines or workplace safety protocols for specific information.
Step-by-step explanation:
When manually handling stacks of lumber, there are specific safety rules to follow to prevent injury. The Occupational Safety and Health Administration (OSHA) has guidelines that mention the safe stacking height, but without specifics to this scenario, a general rule of thumb for manual handling is to keep stacks at a safe working height. If we refer to similar guidelines such as those for pallets, they should generally not exceed six feet when being manually handled to reduce the risk of injury. This height ensures that materials are within easy reach without requiring workers to exert themselves unnecessarily and minimizes the risk of the stack becoming unstable. However, for a definitive answer to the question, it's advised to refer to the specific workplace's safety protocols or OSHA guidelines that pertain to lumber stacking.
Concerning the calculation requested by a group of students regarding stacking books and determining how many they could stack before the pile tipped, they would need to know the dimensions of the books and the principles of the center of gravity. The leaning stack of books would essentially form a cantilever structure, and each book's position would alter the center of mass for the entire stack. They can calculate how far the center of gravity can shift before it goes beyond the base of the bottom book, which would cause the stack to tip.