a) A pair of 20 degree full depth involute spur gears having 30 and 50 teeth respectively of module 4mm are in mesh. The smaller gear rotates at 1000 rpm. Determine-
1) Contact Ratio 15
2) Sliding velocity at engagement and at disengagement of pair of a teeth.
b) Two spur wheels have 30 teeth each of involute shape. The circular pitch is 25mm and pressure angle is 20 degree. Evaluate the addendum of the wheels, if the arc of contact is twice the circular pitch.