Question

A body of mass 100 kg with natural frequency 10 rad/sec has critical damping:

1. 100 N/m/sec
2. 2000 N/m/sec
3. 3142 N/m/sec
4. 10 N/m/sec

Answer 1

Correct Answer - Option 2 : 2000 N/m/sec

Concept:

The coefficient of damping is given as,

C = 2mζω_n where, C = coefficient of damping, m = mass of a body, ζ = damping factor, ω_n = natural frequency    

And Critical coefficient of damping is given as, C_c = 2mω_n  .......(ζ = 1 for Critical damping) 

Calculation:

Given:

m = 100 kg, ω_n = 10 rad/sec,

Therefore, C_c = 2 × 100 × 10 = 2000 N/m/sec