flinnsci.com 379
Mechanics—Rotational, continued
Centrifugal Circle
Help students understand centripetal force while they dispel popular misconceptions
about centrifugal force. A vivid demonstration of Newton’s first law of motion—the
law of inertia. Students watch a ball roll along a circular course. They then predict
what will happen when the ball exits the wooden circular pattern. Will it continue on
its circular path, does it curve away from the circle, or does it follow a straight line?
Students may be surprised with the result! A great apparatus to use in conjunction
with the Centripetal Force Apparatus, AP9164. Includes large wood ball and complete
instructions.
Catalog No. Description Price/Each
AP6471 Centrifugal Circle $72.35
MECHANICS—ROTATIONAL continued on next page.
PHYSICS & PHYSICAL SCIENCE MECHANICS
Centrifugal Circle
AP6471
Circular Motion Paradox—Demonstration Kit
AP6382
Galileo’s Paradox—Hinged Stick vs. Falling Ball
Demonstration Kit
AP6693
Circular Motion Paradox—
Demonstration Kit
By: The Flinn Staff
Just spin the device by hand and watch the tethered bobbers move almost “magically”
into the center of the circle and not to the outside as you might expect. When
you accelerate around a sharp circle in your car, you get thrown to the outside.
Why then do the bobbers seem to do just the opposite?
Catalog No. Description Price/Each
AP6382 Circular Motion Paradox—Demonstration Kit $61.40
Galileo’s Paradox—
Hinged Stick vs. Falling Ball
Demonstration Kit
By: The Flinn Staff
A stick with a cup near one end and a hinge at the other is propped at an angle
with a support rod. A ball is placed on the end of the stick so that the ball is
below the lip of the cup. The support rod is swiftly pulled out, the ball and stick
fall simultaneously, resulting in the ball landing in the cup! Did the stick really
fall faster than the free-falling ball? After students study the apparatus they will
recognize that the stick does not actually “free fall.” The stick rotates as it falls
because of the hinge, and this causes the end of the stick to accelerate faster
than its center of mass, allowing the end of the stick to beat the ball to the ground.
Note: A support stand is required and available separately.
See free video at flinnsci.com.
Catalog No. Description Price/Each
AP6693 Galileo’s Paradox—Hinged Stick vs. Falling Ball
Demonstration Kit
$53.70
AP4550 Support Stand, Economy Choice 13.75
Torque About It
Students discover firsthand how the balance point of a system is affected by mass
distribution. First, they measure the mass of a randomly selected plastic tube, steel
rod and wood dowel. Next, they combine the pieces in a specific configuration and
calculate the center of mass for the system. Finally, they confirm the system’s center
of mass by testing the balance point position of the system. Students will find the
balance point and the center of mass to be the same. Since the plastic tubes and
steel rods have various lengths, each student group will have one of 25 different
combinations. Comes complete with instructions and enough materials for five
groups of students.
Catalog No. Description Price/Each
AP4603 Torque About It $106.00
Torque About It
AP4603
Torque Feeler
Successfully teach the concept of the “rotating force,” or torque, with this unique
device. First, place the hanging mass close to the gripping handle. Students will
find it easy to hold the rod horizontal. Then, slide the same mass to the end of the
rod—not even your strongest student will be able to grip tightly enough to prevent
the handle from twisting in their hands! Effectively demonstrates how lever-arm
distance influences the strength of a torque. Comes complete with instructions and
1-kg hooked mass.
Catalog No. Description Price/Each
AP4621 Torque Feeler $69.75
Torque Feeler
AP4621
/flinnsci.com
/flinnsci.com
/
/
/
/
/
/
/
/
/
/
/
/