Levers & Pulleys: Simple Machines That Make Work Easier

What You’ll Need

Build & Test

1. Make a Lever

1. Put the pencil on a stack of erasers near one end of the ruler. This is the Fulcrum.
2. Clip a paper clip on the short side of the ruler – that’s the Load.
3. Press down on the long side with your hand – that’s the Effort.

Try moving the fulcrum closer to the load. Does the effort feel easier or harder?

2. Make a Fixed Pulley

1. Thread the string through the hole in the spool or bottle‑cap.
2. Tie one end of the string to a paper clip (the Load).
3. Hold the wheel up (the Fixed Pulley) and pull the free end of the string down.

Notice how the load rises while you pull.

3. Try a Compound Pulley

1. Tape a second wheel next to the first one so the string runs over both.
2. Pull the free end of the string.

You should feel that the pull is lighter because the load is shared.

4. Record Your Findings

• Write how far the lever arm moved.
• Count how many pulls it took to lift the load with each pulley set‑up.
• Which arrangement felt the easiest? Write a short reason.

Safety First

• Keep fingers away from the moving rope.
• Use only light loads – heavy things can break the ruler or string.
• Work on a flat table so the lever does not slip.

Quick Quiz

1. What Part Of A Lever Is The Fulcrum?
   a) Effort point b) Pivot point c) Load

2. If You Add More Wheels To A Pulley, The Effort Needed To Lift The Load:
   a) Stays the same b) Increases c) Decreases

3. Which Class Of Lever Has The Effort Between The Fulcrum And The Load?
   a) Class 1 b) Class 2 c) Class 3

Great job! You’ve seen how levers and pulleys let engineers do big jobs with little force.

Answer Key

1. B) Pivot point ✓
2. C) Decreases ✓
3. C) Class 3 ✓

Keep experimenting and have fun discovering how simple machines make work easier!