Question
A body falling from a vertical height of 10m pierces through a distance of 1m in sand. It faces an average
retardation in sand equal to?
[Answer is in terms of 'g' i.e acceleration due to gravity ]
Joshi sir comment
velocity at the time of impact
v2 = 02 + 2g10
now in sand this velocity becomes 0 in 1 m
so 02 = 20g - 2a(1)
so a = 10g