Subjective Type

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.

Solution

$$u=350\ m/s, s=5\ cm=0.05\ m, v=0$$
Deceleration $$=a=\dfrac {v^2 -u^2}{2s}=\dfrac {0-(350)^2}{2\times 0.05}=-12.2\ 10^5 \ m/s^2$$.
Deceleration is $$12.2\times 10^5 \ m/s^2$$.

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