Concept explainers
A uniform disk, initially at rest and of constant thickness, is placed in contact with the belt shown, which moves at a constant speed
(a)
The number of revolutions executed by the disk before it reaches a constant angular velocity.
Answer to Problem 17.135RP
Disk will take
Explanation of Solution
Given:
Velocity of disk
Concept used:
Principle of work and energy.
Calculation:
Angular velocity,
Moment of inertia
Kinetic Friction
Summation of forces at y-direction,
Work was done
Applying the principle of work and energy,
Conclusion:
We can calculate the number of rotations done by disk before reaching constant angular velocity are
(b)
The time taken by disk to reach the constant angular velocity.
Answer to Problem 17.135RP
The time required for the disk to reach the constant angular velocity is
Explanation of Solution
Given:
Velocity of disk
Concept used:
Principle of impulse and momentum.
Calculation:
According to impulse momentum principle.
Taking moments about A,
Conclusion:
Thus, the time taken by disk to reach a constant angular velocity is
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Chapter 17 Solutions
Vector Mechanics for Engineers: Dynamics
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