A drilling operation is performed on a steel part using a 12.7 mm diameter twist drill with a point angle of 118 degrees. The hole is a blind hole with a depth of 50 mm. Cutting speed=15 m/min, and feed=0.20 mm/rev.

Determine the following:

a. Rotational speed of the drill
b. Feed rate
c. Approach allowance
d. Cutting time
e. Metal removal rate after the drill bit reaches full diameter.

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false