Question

Bullet B weighs 0.5 oz and blocks A and C both weigh 3 lb. The coefficient of friction between the blocks and the plane is MK = 0.39. Initially the bullet is moving at Vo and blocks A and Care at rest (Figure 1). After the bullet passes through A, it becomes embedded in block C and all three objects come to stop in the positions shown (Figure 2). Determine the initial speed of the bullet vo. (Round the final answer to the nearest whole number.) C 6 in. 4 in. B A C 12 The initial speed of the bullet is ftis

Answer 1

12 Block B By conservation of energy Kinetic energy of bullet is energy dissipated in friction force of block. equal to the I'mu? 2 buttet [emgr] A block + [umgr sblock I X0.03125 X V. 2 ع 2 Block A + [0-39x3X 324,41] (0-39x3 x32-2x4 *8'03/25 X Vo?- 18.837 + 12.556 { x0º03125 X623 2 g = 32.2 ft/s 31.395 Voz 2009:28 V. 44.825 ft/s LOZ z 0.062516 o soz a 0.0312516 ift 12 inch 6inch 6 ft 12 2 similarly U ~ 45 ft/s Ainch eft 12 The initial speed of bullet is 45 ft/s