The position of a particle is defined by {r = 5*cos(2t) i + 4*sin(29 j, m), where t is in seconds and the arguments for the sine and cosine are given in radians. determine the magnitudes of the velocity of the particle when t=2 seconds. a)-8.20 m/sec b)-8.60 m/sec c)-9.00 m/sec d)-9.18 m/sec

Aturning operation is performed with following conditions: rake angle of 12°, a feed of 0.35 mm/rev, and a depth of cut of 1.1 mm. the work piece is aluminum alloy 6061 with t6 heat treatment (a16061-t6). the resultant chip thickness was measured to be 1.0 mm. estimate the cutting force, fc. use shear stress of 207 mpa and coefficient of friction on the tool face of 0.6.