What best defines a complex machine?

What best defines a complex machine?

• A. A machine made up of two or more simple machines working together
• B. A machine made of a single simple machine
• C. A machine used only in food processing
• D. A simple device for measuring temperature

Answer: (A)

A complex machine is built from two or more simple machines working together to make work easier. Simple machines—like levers, inclined planes, screws, wedges, pulleys, wheels and axles, and possibly inclined planes—reduce effort or change the direction of a force. When you combine several of these, their effects add up, allowing the system to perform tasks that a single simple machine couldn’t do efficiently. That’s why a bicycle, which uses a lever (pedals) and wheel-and-axle and gearing to transfer and multiply motion, is a complex machine. The other options don’t define a complex machine. A machine made of a single simple machine isn’t complex, and the purpose or context (food processing) or being a measuring device doesn’t establish complexity.

A complex machine is built from two or more simple machines working together to make work easier. Simple machines—like levers, inclined planes, screws, wedges, pulleys, wheels and axles, and possibly inclined planes—reduce effort or change the direction of a force. When you combine several of these, their effects add up, allowing the system to perform tasks that a single simple machine couldn’t do efficiently. That’s why a bicycle, which uses a lever (pedals) and wheel-and-axle and gearing to transfer and multiply motion, is a complex machine.

The other options don’t define a complex machine. A machine made of a single simple machine isn’t complex, and the purpose or context (food processing) or being a measuring device doesn’t establish complexity.