how to calculating critical angle for a glass and air interface when there is a total internal reflection between them.​

total internal reflection

.) the observation by semmelweis that more mothers died of childbed fever when their doctors also worked in the morgue

the tires are rotating at 0.434 rpmlinear speed=45 m/sdiameter=0.550 mradius=0.275 mnow v= rωω= v/rω=45/0.275ω=163.6 rad/sω=163.6 rad/s (1rev/2π rad) (60s/1m)ω=1563 rpm