$20$

$3$ a$)$ Explain dynamic load carrying capacity of rolling element bearings. State its relation to bearing load and bearing life.

b$)$ The radial load acting on a ball bearing is $2500$ N for the first five revolutions and reduces to $1500$ N for the next ten revolutions. The load variation then repeats itself. The expected life of the bearing is $20$ million revolutions. Determine the dynamic load carrying capacity of the bearing.

c$)$ Explain different types of rolling contact bearings.