Which of the following is a simple machine?

Which of the following is a simple machine?

• A. Computer
• B. Refrigerator
• C. Car engine
• D. Lever

Answer: (D)

A lever is a simple machine because it uses one rigid bar that pivots on a fixed point called a fulcrum to multiply our effort or change its direction. By placing the load and the input force at different distances from the fulcrum, you can lift a heavy object with less force, which is exactly what a simple machine does—make work easier. The other items are complex devices made from many parts and different mechanisms working together, not single basic machines.

A lever is a simple machine because it uses one rigid bar that pivots on a fixed point called a fulcrum to multiply our effort or change its direction. By placing the load and the input force at different distances from the fulcrum, you can lift a heavy object with less force, which is exactly what a simple machine does—make work easier. The other items are complex devices made from many parts and different mechanisms working together, not single basic machines.