Wednesday, 18 December 2019 14:02

## B1-18: Center of Mass - Soda Can and Water

• ID Code: B1-18
• Purpose: To demonstrate how an object's behaviour can change when its center of mass does
• Description: An empty soda can can sit upright on its bottom, or can be laid on its side, but cannot be at rest at any angle between these. However, this can be changed by adding a liquid to the system. Pour approximately 150ml of water into the can, and then try carefully balancing the can at an angle, as seen in the photo above. (This may require experimenting to find the exact right amount of water for any given can; we recommend doing this in front of the class so they can see the process.)

Ask your students why this should happen? The mass has increased, but why does that change how it balances?

The water moves when the can tilts, causing the center of mass to shift – with just the right amount of water, the new center of mass will be above the edge of the can, and so it will balance.

Some cans will tend towards a particular orientation and will roll along the edge to that point, displaying a damped oscillation – invite students to hypothesize why this is.

• Availability: Available
• #### 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
• 1