183_notes:examples:rotational_angular_momentum_of_a_bicycle_wheel

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A bicycle wheel has a mass of 0.8kg and a radius of 32cm. If the wheel rotates in the xz plane, spinning clockwise when viewed from the +y axis, and making one full revolution in 0.75 seconds, what is the rotational angular momentum of the wheel?

Facts

Mass of bicycle wheel = 0.8kg.

Bicycle wheel has a radius of 32cm.

Bicycle wheel is spinning clockwise when viewed from the +y axis.

Bicycle wheel rotates in the xz plane.

Bicycle wheel completes one full revolution in 0.75 seconds.

Lacking

The rotational angular momentum of the wheel

Approximations & Assumptions

Representations

Equation for moments of inertia for a hoop: $I=MR^{2}$

$\omega = \frac{2\pi}/{T}$

Solution

The direction of $\vec{\omega}$ is -y.

$I = MR^{2} = (0.8kg)(0.32m)^2 = 0.082 kg \cdot m^2$

$\omega = \frac{2\pi}{0.75s} = 8.38 s^{-1}$

$\mid\vec{L}_{rot}\mid$ = $(0.082 kg \cdot m^2)(8.38 s^{-1}) = 0.69 kg \cdot m^2/s$

$\vec{L}_{rot} = \langle 0, -0.69, 0 \rangle kg \cdot m^2/s$

  • 183_notes/examples/rotational_angular_momentum_of_a_bicycle_wheel.1416467197.txt.gz
  • Last modified: 2014/11/20 07:06
  • by pwirving