Eureka! The Archimedes Balance


Cynthia Houseby: Cynthia House

I sponsor an after school Science Club in a K-5 elementary school. The club is organized into two-week-long sessions, each session focusing on a specific topic. One of this year’s most successful sessions involved the Archimedes Balance from Educational Innovations.

Archimedes Balance Experiment 1:

  • calculators
  • answer sheet, listing the sample materials and their densities
  • fill-in table to record findings:

Students worked in pairs with first and second grade children teamed with a fourth or fifth grade student. We introduced the topic with a brief Power Point biography of Archimedes and his accomplishments, focusing on the story of King Hieron’s crown. Then students practiced determining the density of materials using the Archimedes balance and the samples supplied in the sets (all directions are included in the kit).

Archimedes BalanceThe Archimedes Balance relies on Archimedes’ principle which states that a floating object displaces its own weight of fluid.  The balance consists of a graduated cylinder partially filled with water and a tube that fits inside the cylinder and can float in the water.  By placing an object inside the inner tube and measuring the amount of water displaced, you can easily determine the objects weight. Read the rest of this entry »


High School Density Kits


Ron Perkinsby: Ron Perkins

Whether teaching general science, chemistry or physics, one of the first experiments I assigned was to determine the density of a metal using a set of different sized cylinders of aluminum in a tray.

Each Student:

  • Determined both the mass and volume of a single assigned sample.
  • Recorded their data point on a large classroom Mass vs. Volume Graph.
  • Participated in a class discussion on: determining volume by different methods; drawing a straight line through the data points (including the origin); and calculating the slope of the line (rise over run)

Density Graph

Ron’s suggestions:

Classroom Density Assortment 1. The Density Sphere Experiment Kit (DEN-10) or Steel Sphere Density Kit (DEN-350) are ideal beginning sets. The Density Paradox (DEN-300) is interesting as the solid object sinks and then floats in one beaker of water, but when put into a second beaker of water, it floats at first and then sinks. The Poly Density Kit (DEN-460) is interesting because Read the rest of this entry »