True or False: Machines require an input of energy to produce an output of energy.

Machines indeed require an input of energy to produce an output of energy, making the statement true. This is a fundamental concept in physics and engineering. When a machine operates, it transforms input energy, which could come from various sources such as electrical power, human effort, or other forms of energy, into useful work or output energy. The efficiency of the machine may vary, meaning not all input energy is converted to output energy, as some may be lost due to friction or heat.

Understanding this principle is crucial since it highlights the relationship between energy input and work output, which is integral to the operation of simple machines like levers, pulleys, and inclined planes, as well as more complex machinery.