WFU Department of Physics Wake Forest University

 

Wake Forest Physics
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WFU Physics Lecture Demonstrations

Bicycle Wheel Gyro

PIRA 1Q50.20

Image:

Photo of Demo

Description:

"The angular momentum is a vector pointing along the axis about which the gyroscope spins (in a sense given by the right-hand rule). In the absence of external torques, the direction as well as the magnitude of this vector will remain constant. Friction produces a torque that decreases the magnitude of the vector and eventually causes the gyroscope to stop spinning. Gravity produces a torque perpendicular to both the axis of the gyroscope and the vertical, and thus causes the horizontal precession. On a less abstract level, the precession can be explained in terms of the downward pull of gravity that tries to make the wheel rotate faster at the bottom than at the top. Since the wheel is rigid, this can happen only if the wheel moves horizontally in the direction in which the bottom of the wheel is spinning. The earth is a large gyroscope that precesses once every 26,000 years due to the gravitational torque exerted by the sun on the slight bulge at the equator." 

Recipe and
Location:

Bicycle Wheel
Rope Attatchment

Video:

Streaming Video:

Bicycle Wheel Gyro

MPG Video:

None

Real Video:

None

Notes:

 

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100 Olin Physical Laboratory
Wake Forest University
Winston-Salem, NC 27109-7507
Phone: (336) 758-5337, FAX: (336) 758-6142
E-mail:
wfuphys@wfu.edu