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What is the critical speed of the shaft if its natural frequency of transverse vibration is 2.85 Hz?

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ESE Mechanical 2021 Official Paper
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  1. 171 rpm
  2. 285 rpm
  3. 570 rpm
  4. 142.5 rpm

Answer (Detailed Solution Below)

Option 1 : 171 rpm
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Detailed Solution

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Concept:

The relation between time-period (T), angular velocity (ω) and frequency (f) is given by:

We know that angular velocity (ω) can be represented in terms of angular speed (N):

Calculation:

Given:

f = 2.85 Hz

ω = 2πf ⇒ 2π × 2.85 Hz

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