A pair of spur gears with 20°, full-depth, involute teeth transmits 7.5 hp. The pinion is mounted on the shaft of an electric motor operating at 1750 rpm. The pinion has 20 teeth and a diametral pitch of 12. The gear has 72 teeth. Compute the following: 

a. The rotational speed of the gear 

b. The velocity ratio and the gear ratio for the gear pair 

c. The pitch diameter of the pinion and the gear 

d. The center distance between the shafts carrying the pinion and the gear 

e. The pitch line speed for both the pinion and the gear 

f. The torque on the pinion shaft and on the gear shaft 

g. The tangential force acting on the teeth of each gear 

h. The radial force acting on the teeth of each gear 

i. The normal force acting on the teeth of each gear.