M.1 - Simple and Compound Machines

Which of the following is a type of simple machine?

• Lever

• Engine

• Gear

• Circuit

Identify the compound machine from the following examples.

• Scissors

• Pulley

• Inclined Plane

• Wedge

Calculate the mechanical advantage of a lever where the effort arm is 4 meters and the load arm is 1 meter.

• 1

• 2

• 3

• 4

Which of the following statements best describes the relationship between work and energy?

• Work is the rate at which energy is used.

• Work is the energy transferred to or from an object via the application of force along a displacement.

• Work is the energy stored in an object.

• Work is the energy lost due to friction.

A bicycle is an example of which type of machine?

• Simple Machine

• Compound Machine

• Complex Machine

• None of the above

If a machine has an efficiency of 75% and the input work is 200 J, what is the output work?

• 100 J

• 150 J

• 175 J

• 200 J

Explain how a pulley system can be used to lift heavy objects with less effort. Provide a real-world example.

• A pulley system reduces the amount of force needed by increasing the distance over which the force is applied. An example is using a block and tackle system to lift a car engine.

• A pulley system increases the force needed by decreasing the distance over which the force is applied. An example is using a single fixed pulley to lift a bucket.

• A pulley system does not change the force needed but changes the direction of the force. An example is using a flagpole pulley to raise a flag.

• A pulley system increases the speed of lifting without changing the force needed. An example is using a conveyor belt system.

Which of the following is NOT a simple machine?

• Wheel and Axle

• Screw

• Lever

• Motor

A ramp is used to lift a 500 N object to a height of 2 meters. If the length of the ramp is 5 meters, what is the mechanical advantage of the ramp?

• 0.4

• 2.5

• 5

• 10

Discuss the efficiency of simple machines and how friction affects it. Provide an example of a simple machine where friction is a significant factor.

• Simple machines are always 100% efficient because they do not lose energy. Friction does not affect them. An example is a lever.

• Simple machines are never efficient because they always lose energy to friction. An example is a pulley with a rough rope.

• Simple machines can be efficient, but friction reduces their efficiency by converting some input work into heat. An example is a wheel and axle with a rough surface.

• Simple machines are efficient only when used in a vacuum. Friction is not a factor. An example is a screw.