Topics: Mass, Lever, Simple machine Pages: 3 (525 words) Published: August 29, 2013
Balancing the Load: The See-Saw as a Simple Machine
Introduction
The see-saw is not just a playground toy, it is an example of a simple machine. In physics, simple machines are tools that make it easier to do work. A lever is an example of a simple machine. A lever is a straight rod or board that pivots on a stationary point called a pivot point or a fulcrum. Levers are often used to lift heavy loads. A see-saw, a shovel, and a wheelbarrow are all examples of levers. Abstract

Have you ever tried to pull out a nail out of wood with your bare hands? Or have you tried to shove a staple through a stack of papers without a stapler? A hammer's claw, a stapler, a pair of pliers and a shovel are each examples of everyday tools that use levers to make our work easier. Objective

In this experiment, you will use a playground see-saw to investigate how a simple machine works. The objective is to learn the relationship between mass and distance when the see-saw is balanced and unbalanced. Terms and Concepts

* lever
* fulcrum
* mass
* weight
Materials and Equipment
* see-saw
* tape measure
* bathroom scale
* two children of approximately the same weight

Experimental Procedure
1. Determine the mass of each of the people participating in the experiment using the scale. (If your scale is calibrated only in pounds, you can convert to kilograms by multiplying by 0.454 kg/lb.) Record the mass of each participant in lab notebook. (For this sample procedure, we will refer to the participants using the following code: Adult=A, First child=C1, Second child=C2.) 2. Have C1 and C2 sit on the see-saw. Have C1 and C2 adjust their positions until the two masses are balanced. Measure the distance of each mass from the fulcrum. (Note: The distance should be measured along the side of the lever from the center line of the fulcrum to the center line of each mass. If your tape measure is calibrated only in inches, you can convert to...