# Scientific Reasoning

## G1-81: OUIJA WINDMILL

Purpose: Illustrate a combination of simultaneous orthogonal oscillations.

## B4-04: SPRING AND STRING THING

Category: B4 Elasticity
Purpose: Illustrate series and parallel springs in a counterintuitive way.

## C5-41: HOURGLASS PROBLEM

Purpose: Demonstrate the solution to the famous "hourglass problem," or Galileo's water bucket

## B3-15: FOOL'S TACKLE

Category: B3 Simple Machines
Purpose: Illustrate analysis of forces in a pulley system

## B2-41: ROBERVAL BALANCE

Purpose: Demonstrate a paradox in equilibrium of forces and torques

## B1-12: CENTER OF MASS - HINGED STICK PARADOX

Purpose: Illustrate the center of mass in a surprising way

## G2-07: PSYCHOACOUSTIC VIBRATION TRANSDUCER

Purpose: Challenge your students to recognize pseudoscience while illustrating resonance

## C5-02 SPRING AND PULLEY PARADOX

Purpose: Show that the action-reaction pairs have equal magnitude
• #### B1-01 CENTER OF MASS - DISC SECTION

Demonstrate finding center of mass for an irregularly-shapped object Read More
• #### B1-02: CENTER OF MASS - LEANING TOWER

Demonstrate the effect of center of mass location Read More
• #### B1-03: CENTER OF MASS - LEANING TOWER ON INCLINED PLANE

Demonstrate equilibrium when its center of mass is above its base Read More
• #### B1-04: Center of Mass - Brass Barbell

Demonstrate stable equilibrium when supported at center-of-mass Read More
• #### B1-05: CENTER OF MASS - PLUMBER'S HELPER

Locate the center of mass of an irregular object Read More

• #### B1-08: STATES OF EQUILIBRIUM - CONE

Illustrate stable, unstable, and neutral equilibrium Read More
• #### B1-09: CENTER OF MASS - TRIANGLE

Demonstrate the process of locating the center of mass Read More

• #### B1-12: CENTER OF MASS - HINGED STICK PARADOX

Illustrate the center of mass in a surprising way Read More
• #### B1-13: CENTER OF MASS - FORK AND SPOON ON TOOTHPICK

Illustrate the center of mass in a surprising way Read More
• #### B1-14: CENTER OF MASS - BOTTLE

Illustrate the center of mass in a surprising way Read More
• #### B1-15: TOPPLING CYLINDERS

Illustrate stable and unstable equilibrium in a surprising way Read More
• #### B1-16: CORBELED ARCH

Illustrate how the center of mass affects the stability of an arch Read More
• #### B1-17: CENTER OF MASS - STICKS

Illustrate the center of mass in a surprising way Read More
• #### B1-18: Center of Mass - Soda Can and Water

Show how moving the center of mass of an object changes how it balances. Read More
• #### B1-21: BALANCE BEAM - VARIATION ON THE TIGHTROPE WALKER

Show how arms or a pole are used to obtain greater stability Read More
• #### B1-22: CENTER OF GRAVITY USING TEETER TOTTER

Determine the center of gravity of the human body Read More
• #### B1-24: CENTER OF MASS - CARTS ON BALANCE BOARD

Show that the center of mass may remain at rest during motion within the system Read More
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