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Grade upto college level Mechanics

A gyroscope consists of a rotating disk with a 48.7-cm radius suitably mounted at the midpoint of a 12.2-cm-Iong axle so that it can spin and precess freely. Its spin rate is 975 rev/min. The mass of the disk is 1.14 kg and the mass of the axle is
130 g. Find the time required for one precession if the axle is supported at one end and is horizontal

Profile image of Shane Macguire
11 Years agoGrade upto college level
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1 Answer

Profile image of Deepak Patra
11 Years ago

To calculate the time required for one precession of the gyroscope, we need to consider the principles of angular momentum and precession in physics.

Understanding the Gyroscope Setup

In this scenario, the gyroscope consists of a rotating disk with a 48.7-cm radius mounted on a 12.2-cm-long axle. The spin rate of the gyroscope is 975 rev/min. The mass of the disk is 1.14 kg, and the mass of the axle is 130 g.

Calculating Angular Momentum

The angular momentum of the gyroscope is given by the formula:

\( L = I \cdot \omega \)

Where \( L \) is the angular momentum, \( I \) is the moment of inertia, and \( \omega \) is the angular velocity.

The moment of inertia of the gyroscope can be calculated using the formula for a solid disk:

\( I = \frac{1}{2} m r^2 \)

Where \( m \) is the mass of the disk, and \( r \) is the radius.

Substituting the given values, we find:

\( I = \frac{1}{2} \times 1.14 \, kg \times (0.487 \, m)^2 \)

Determining Precession Time

The precession time can be calculated using the formula:

\( T = \frac{2\pi I}{L} \)

Where \( T \) is the precession time, \( I \) is the moment of inertia, and \( L \) is the angular momentum.

Substituting the calculated values for \( I \) and angular momentum, we can determine the precession time of the gyroscope.

By solving the above equations, we can find the time required for one precession of the gyroscope when the axle is supported at one end and is horizontal.