Number of pads = 4

Static deflection = $\delta st$ = 5mm = 0.005m

M = 300 kg

$\eta_{iso} = 95%$

N = ?

$\xi \ = \ 0$

$\eta \ iso \ = \ 1 - T_r$

0.95 = 1 – $T_r$

$T_r$ = 0.05

$Tr = \frac{\sqrt{1 + (2 \xi r)^2}}{\sqrt{ (r^2 – 1)^2 + (2 \xi r)^2}}$

$0.05 = \frac{1}{r^2 – 1}$

$r^2 – 1 = 20$

$r^2 = 19$

r = 4.358

$w_n = \sqrt{ \frac{9}{\delta_{st}}} = \sqrt{\frac{9.81}{0.005}} = 44.29 $ rad/sec

$r = \frac{w}{w_n}$

$4.358 \times 44.29 = w$

w = 202.86 rad/sec

$w = \frac{2 \pi N}{60}$

N = 85857.86 rpm.