Question

A bullet of mass 30 g, and moving with a velocity x hits a wooden target with a force of 187.5 N. If the bullet penetrates 80 cm, find the value of x

Answer 1

Mass of bullet = m = 30 g = `30/1000` kg = 0.03 kg
Force = F = 187.5 N
Acceleration = a = ?
Acceleration = a = `-"F"/"m"` ........[because of retardation]

a = `-187.5/0.03`

= `-18750/3` = −6250 ms⁻²

Initial velocity = u = x
Final velocity = v = ?
Distance covered by bullet = S = 80 cm = `80/100` m
S = 0.8m
v² – u² = 2aS
(0)² – (x)² = 2 × (–6250) × 0.8
–x² = –10000
x² = 10000
x = `sqrt10000` = 100 ms^–1