Question

Questions 13-15: At t=0 the current to a dc electric motor is reversed, resulting in an angular displacement of the motor shaft given by e(t) = (27 rad/s)t - (1 rad/s°) (10 points) 13) At what time is the angular velocity of the motor shaft zero? 14) Calculate the angular acceleration at the instant that the motor shaft has zero angular velocity. 15) The radius of the shaft is 0.1m. Calculate the linear speed of the shaft at t=1s and its linear acceleration is Questions 16-17: Block A mA = 5.00 kg, and block B has a mass me = 5.00 kg underwent a head of collision. After the collision they stick together and moved at unknown speed. The initial speeds of Block A and Block B are 5 m/s respectively. Block A was moving to the right and Block B was moving to the left (5pts) 16) Calculate the final speed of the two after the collision b) inelastic or c) unknown (2 pts) 17) Is this collision a) Elastic or

Answer 1

briven, o(t) = 27 (oad/s) t - (1sad | 53) ť 13 waa at t=a. we=do - agd (274-1 t) e dt dt = 27 - 3t² = 0 => 3+2 = 27 t2 = q tgs so, It=3s At t=35, ang. relocity =o. 14 At t=3s , & = ? da due #24 - 3+) x = 0 - 6t At t= ss, x = -6x 3 rad/s2 x = - 18 rad/ ² (- he because relocity is (x = 18 rad/s2 Ang decreasing) (6) R = 0.1m At t is W = (27-3x 12 ) sadis we = 24 sadis use v= rue = 0.1m x 2 4 radis - 2.4 ms

and a at t=1s x = - 6t radg2 a - 6 rad/s2 a = 8x = 0.1 x 6 m/s2 a = .6 m/s 2 ans ) MA= 5kg, MB = 5kg VA = 5ml VB = 5 m/s Use momentom conservation, MAVA - MB VB = (MA+MB) Vf ve [(5x5) - (sx)) leg mis so - 10kg [if = o mis an (17) Collison In case of the collision moves with is inelastic. inelastic collision after masses stick together and common speed