Question

a bullet strikes a target with initial velocity 30 metre per second and comes to rest after penetrating a distance 45 CM calculate the retardation caused by the target and the time of p**********

Answer 1

use
${v}^{2} - {u}^{2} = 2as$
initially u=30m/s and v=0m/s so using this -900=2×0.45×a then we get a=-1000m/S2 then using v=u-at so we get t=0.03 seconds