Day 26 of 30
Simple machines: lever and pulley
Content is AI-assisted and continuously improved through educator review
Learning Objective
Students will be able to explore simple machines and lever and pulley.
In this lesson, we'll explore simple machines: lever and pulley. Scientific inquiry allows us to investigate and explain natural phenomena.
Simple machines reduce the force needed to do work by increasing distance. The six simple machines: Lever (bar rotating on a fulcrum—three classes based on fulcrum, load, effort positions), Wheel and axle (larger wheel amplifies force), Pulley (changes direction of force; multiple pulleys reduce force needed), Inclined plane (ramp—less force over greater distance), Wedge (two inclined planes—concentrates force), Screw (inclined plane wrapped around a cylinder). Mechanical advantage (MA) = output force ÷ input force = how much a machine multiplies force. A MA of 3 means the machine triples the applied force. Work = Force × Distance (W = Fd), measured in joules; a machine doesn't reduce the work done—it changes how force and distance trade off. Real machines have friction, so actual MA is less than ideal (theoretical) MA. Simple machines are combined in compound machines: bicycles, scissors, wheelbarrows.
As you work through today's material, pay attention to the examples and try to identify the patterns or strategies being used. This will help you apply these concepts to new problems.
Take notes on key points and make connections to what you've already learned in previous lessons.
To examine systematically through observation and experiment
Observable facts that support or refute a claim
Instructions
Materials Needed
- Lab notebook
- Investigation materials
- Safety equipment if needed
Based on today's lesson, what is one thing you observed or learned?
How could you test or investigate this topic further?
Why is this topic important in the real world?
Teaching Tip
For this age group: Balance direct instruction with collaborative activities. Allow students to explain their thinking and make connections to prior knowledge when exploring simple machines: lever and pulley.