Test 2 EGEN202: Dynamics Please show your work to receive partial credit in the event that your answers are incorrect. Good Luck! (3) Problem: 21/25 points) The telescopic arm AB shown pivots about point A. The radial position of mass B (m = 10 kg) is described by vector r = (in meters). The angular position of the arm is given by @= t (where t is in seconds and is in radians). What is the transverse force (magnitude and direction) acting on mass B when t = 4 seconds. Note: The arm AB starts from rest with motion in the horizontal plane. na3 r = 1, r=0396 r = 565 % = 30t4 solution: Gr=4 -réz 22 Som( r ö + 2 r0) =-622 0:2 =10 / (2) + 2(1)(2+) = - 2t a = -2(413 = -128 =10 (+? (2) + 4+) Assumed ? F r = m (ar) r=0?? = 10 (4²)2 + 4(4) direction 10(-128) dirence - 480N = -1,280N of tean=v² = 9.43) = 0 34 ml? Ray Act 23 262.02 F = man = 3,44 P=26202 ZFj JX (9.81 sint" = sera !! 5' F mar - (loky X2.7m/s) 19.8 Sint=ar => 2.7 m/2 [= 27.040 / 9316-cost -9.43 = 1 1/2 Page 3 of 4 W and 21 P = 1 + 3 %*