1. The problem statement, all variables and given/known data A 10g bullet strikes and becomes embedded in a 0.200kg block of wood placed on a horizontal surface just in front of the gun. If the coefficient of sliding friction between the block and the surface is 0.4 and the impact drives the block a distance of 8m before it comes to rest, what is the velocity of the bullet before it strikes the block of wood? 2. Relevant equations E(kinetic)=E(frictional) 1/2(m1+m2)v2^2=μ(m1+m2)gs or ma=μmg a=μg v^2=u^2+2as v1(m1)=v2(m1+m2) 3. The attempt at a solution I've tried 2 different ways to do it which are: 1.) m1=0.010kg m2=0.200kg s=8m μ=0.4 1. E(kinetic)=E(frictional) 1/2(m1+m2)v^2=μ(m1+m2)gs 1/2(0.210)v^2=0.4(0.210)(9.8)(8) v2=7.92m/s m1v1=(m1+m2)v2 0.010v1=0.210*7.92 v1=166.32m/s 2.) ma=μmg a=μg a=0.4*9.8 a=3.92 v^2=0 a=-3.92 s=8m u^2=? v^2=u^2+2as 0=u^2+2(-3.92)(8) u^2=7.92 m1v1=(m1+m2)v2 0.010v1=0.210*7.92 v1=166.32m/s I'd love to know if I'm on the right track here. Thanks a million in advance.