Question

A machine part having a mass of 2.5 kg vibrates in a viscous medium. A harmonic exciting force of 30 n acts on the part and causes a resonant amplitude of 14 mm with a period of 0.22 seconds. Find the damping coefficient. If the frequency of the exciting force is changed to 4 hz, determine the increase in the amplitude of the forced vibrations upon the removal of the damper

Answer 1

Answer:

75

right answer

i hope it's help to you

Answer 2

Answer:

Harmonic Exciting Force F, = Angular Speed Wn X Damping Coefficient, c X Resonant Amplitude, x

i.e. F = Wn X c X x

Wn = 2π ÷ T = 2π ÷ 0.22 =28.56 rad/s

c = F ÷( Wn X x) = 30 ÷ (28.56 X 0.014)

= 30 ÷ (0.39984) =

=75.03 Ns/m