A bullet fired into a large block of wood of uniform resistance, hits the block with a velocity of 48ms−1. It penetrates a distance of 60 cm and the velocity is then reduced to 24ms−1. It then penetrates a further distance of (in cm)
u=48ms−1;
v=24ms−1;
s=60100=0.6m
v2−u2=2as
242−4822×0.6=a
a=−1440ms−2
u=24; v=0;
s=v2−u22a
=2422×1440
=0.2m
=20cm