# Wheel and Axle

## Purpose

The wheel and axle operate on the principle of the lever. The center of the axle is the pivotal point, or fulcrum. The mechanical advantage depends on how large around the axle is and the distance traveled by cranking the handle where the effort is applied.

C.L.

## Materials

Wheel and axle apparatus

String or fishing line

Book

Timer

B.O.

## Procedure

Tie one end of the string to the center of the book. Tie the other end of the string to the narrowest part of the axle. When the handle is cranked (fishing handle) the string will wind around the axle, and the books will be lifted more easily. Count the number of turns it takes to reel in the book to the desired height. Record the info in your data table. Now complete this same experiment as before, but with the string tied to the widest part of axle. We actually used a fishing reel as our wheel and axle.

M.P.

## Analyze and Conclude

1. For which axle size does it require a smaller number of turns to lift the books the desired height? Why?

The wider axle because it gathers more line faster.

2. What affect did the sizes of the different axles have on the amount of work done? Explain.

They both did the same amount of work, except the wide one took less time because it gathered more line quicker.

3. How could we determine the mechanical advantage of each of the axles? Which axle has the greatest mechanical advantage?

Resistance force over effort force. The wide axle because it gathered more fishing line faster.

J.C.