A block of wood with a mass M = 4.65 kg is resting on a horizontal surface when a bullet with a mass m = 18 g and moving with a speed v = 725 m/s strikes it.The coefficient of friction between the block and the surface is µ = 0.35.The distance the block moves across the surface is
A)1.1 m
B)3.3 m
C)0.41 m
D)11 m
E)None of these is correct.

Question

Quizplus · Accepted Answer

Explanation:Momentum before impact = mv = (0.018 kg)(725 m/s) = 13.05 kg m/sMomentum after impact = (M + m)v' = (4.668 kg)v'By conservation of momentum, 13.05 kg m/s = (4.668 kg)v'v' = 2.8 kg m/sWork done by friction = (µ)(M + m)g(d) = (0.35)(4.668 kg)(9.8 m/s^2)(d) = 15.98d JKinetic energy after impact = (1/2)(M + m)v'^2 = (1/2)(4.668 kg)(2.8 m/s)^2 = 19.6 JBy conservation of energy, 19.6 J = 15.98d Jd = 1.23 m

A Block of Wood with a Mass M = 4