Final answer:
It is true that an air hammer must be pressed tightly against the workpiece before use for accurate work and safety. High-voltage wires are not insulated; their suspension in the air isolates them. The efficiency of simple machines is always less than 100% due to energy lost as heat due to friction.
Step-by-step explanation:
The correct answer to the question is True. When using an air hammer tool, also known as a pneumatic hammer, it is important to press the tool tightly against the workpiece before turning it on. This is because the tool works through rapid pneumatically-driven hammer strikes to shape or carve the workpiece, and if it is not pressed firmly against the workpiece, it can lead to uncontrolled movements, resulting in inaccurate work or damage to the tool and workpiece. Moreover, it is crucial for safety to have a stable and secure hold on the tool to prevent potential accidents.
Insulating connectors and insulating material: The statement regarding high-voltage wires is false. While it is true that these wires are held aloft by insulators, the wires themselves are not wrapped in insulating materials because they are designed to be suspended in the air, where the surrounding air acts as a natural insulator.
Forces on a ramp: The statement about the force required to push a box up a ramp is False. The actual force required depends on multiple factors, such as the friction between the ramp's surface and the box, as well as the mechanical advantage gained by using the ramp. It cannot be determined to be exactly 100 N without calculating the actual forces involved.
Efficiency of simple machines: The statement regarding the efficiency of simple machines is True. Due to friction and other factors, the efficiency of a simple machine is always less than 100 percent because some input work is converted to heat energy. This is a principle governed by the laws of thermodynamics.