Question

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

Answer 1

Initial velocity, u = 350 m/s
Final velocity, v = 0
Distance travelled by the bullet before coming to rest, s = 5 m
$\mathrm{Acceleration},a=\frac{v^2-u^2}{2s}$
$\Rightarrow a=\frac{0-{\left(350\right)}^2}{2\times 0.05}=-12.2\times {10}^5\mathrm{m}/{\mathrm{s}}^2$
∴ Deceleration = 12.2 × 10⁵ m/s²