Activity 4

Build a lever

STEP 1

Here's the Materials You'll Need:

Ruler (30 cm)

Pencil

Tape

2 paper cups

A small rock or other weight

Handful of pennies

STEP 2: Label and tape the cups

Label one cup “Load” and the other cup “Effort.” Use tape to attach the cups to opposite ends of the ruler.

STEP 3: Add the fulcrum

Position the pencil underneath and perpendicular to the ruler, so the pencil crosses below the 5 cm line. It may be helpful to tape the pencil to the desk so it doesn’t roll around!

STEP 4: Lift the object

Place the rock in the “Load” cup. One by one, place pennies in the “Effort” cup until the load lifts into the air. Record the number of pennies it took using a table like the one below.

STEP 5: Move the fulcrum

Repeat the experience with the pencil placed at 15 cm and 25 cm.

    • How did the position of the fulcrum affect the number of pennies needed to lift the load?

    • How could you modify the lever to make it even easier to lift the load?

    • What are some similarities between a lever and an inclined plane? Differences?

    • What real-life situations would be ideal for using a lever?