Question

nment FULL SCREEN PRINTER VERSION 4 BACK Chapter 3, Problem /262 (video solution to similar problem attached) Two hockey pucks movi with initial velocities va and va collide as shown. The mass of is 7.5 kg. If the coefficien: of restitution is e 0.63, determine the velocity (magnitude and direction 9 with respect to the positive x-axis) of each puck just after impact. Also calculate the percentage loss n of system ki A is 3.0 kg and the mass of E A. 30° VA = 12.2 mis Og= 6.6 m/s enn Answers: Inc. All Rights Reserved. A Division of loha Wile &.Sans Ins

Answer 1

Conservation of linear momentum in x - direction m_A u_A coc(30 Degree) + 0 = M_A V _A_x + M_B V _B_X in y - direction M_A u_A sin 30 Degree + M_B u_B = M_A V_A_y + M_B V_B_y also, elementof = relative velocity . After collision in x - direction /refative velocity.before collision in x - direction = relative . velocity after collision in y - direction /relative .velocity before collision in y - direction e = V_Ax - V_Bx/u_A cos 30 Degree - u/b & e = V_Ay - V_By/u_A sin 30 Degree - u _B we have four unknowns and four equation From 3 0.63 times (12.2 cos30 Degree) = V_Ax - V_Bx put V_Ax in equation (i) 3 times 12.2 cos 30 Degree (1 - 0.63) = 3V_Bx + 7.5 V_Bx V_B_x = 1.1169 m/s V_Ax = 7.773 m/s and , From 4 0.63 times (12.2 sin 30 Degree - 6.6) = V_Ay - V_By - 0.315 = V_Ay - V_By put in 2 3 times 12.2 sin 30 Degree + 7.5 times 6.6 = 3 times (V_By - 0.315) + 7.5 V_By V_By = 6.547 m/s
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