A bullet fired target loses half of it velocity in penetrating 15cm .how much further it will penetrate before coming to rest

Answer 1

OrigKE=1/2 m vi^2
KE at 15cm= 1/2 m (vi/2)^2
remaining KE= 1/2 m vi^2 (1-1/4)= 3/4 oriainal

so, is should then go 3*15cm more...