PIRA #

Demonstration Name

Abstract

1J10.09

center of gravity

Many examples of simple center of mass demonstrations.

1J10.10

map of state

Suspend a map of the state from holes drilled at large cities to find the "center of the state".

1J10.10

map of state

Sandwich of a map of the state between two plexiglass sheets and suspend from holes drilled at large cities to find the "center of the state".

1J10.10

map of Minnesota

A plexiglass map of the state is suspended from several points.

1J10.11

find the center of gravity

Use a chalk line on the plumb bob and snap it to make a quick vertical line.

1J10.12

hanging shapes

Use the plumb bob method to find the center of gravity of various geometric shapes.

1J10.12

hanging board

Suspend an irregular board from several points and use a plumb bob to find the center of gravity.

1J10.12

irregular object center of mass

Suspend an irregular object from several points and find the center of mass with a plumb bob.

1J10.15

hanging potato

Hang a potato from several positions and stick a pin in at the bottom in each case. All pins point to the center of gravity.

1J10.20

meter stick on fingers

Slide your fingers together under a meter stick and they meet at the center of gravity. Add a baseball hat to one end and repeat.

1J10.20

friction and pressure

Slide your fingers under the meter stick to find the center of mass.

1J10.20

meter stick on fingers

Slide your fingers under a meter stick to find the center of mass.

1J10.25

center of gravity of a broom

Bring your fingers together under a broom the find the center of gravity.

1J10.25

center of gravity of a broom

Find the center of gravity of a broom, hang a kg mass somewhere on the broom, find the new center of gravity, calculate the weight of the broom by equating torques.

1J10.26

balance beam and bat

1J10.30

meter stick on fingers

1J10.30

loaded beam - moving scales

Slide the scales together under a loaded beam noting the scale readings of the moving and stationary scales.

1J10.30

loaded beam - moving scales

Instead of moving the masses on the beam, move the scales under the beam. Same as bringing your fingers together under the meter stick.

1J10.41

your center of gravity

Two methods for measuring the center of gravity of a person are shown.