Question

A bullet going with speed 350m/s enters a concrete wall and penetrates a distance of 5.0cm before coming to rest find the decleration

Answer 1

initial speed, u = 350 m/s
displacement, s = 5 cm = 0.05 m
final speed, v = 0 m/s

let acceleration = a

eqn,
${v}^{2} = {u}^{2} + 2as$
$a = \frac{ {v}^{2} - {u}^{2} }{2s} \\ = > a = \frac{ - 350 \times 350}{2 \times 0.05}$
$= > a = - 1225000 \: \frac{m }{ {s}^{2} }$
$deceleration = 1225000 \: m {s}^{ - 2}$