A bullet looses of its velocity passing through one plank

PHYSICS · Single correct · AP · Physics 1: Algebra-based · Work Energy and Power · Work Energy and Power

Problem

A bullet looses

\left(\frac{1}{n}\right)^{th}

of its velocity passing through one plank. The number of such planks that are required to stop the bullet can be: (1)

\frac{n^2}{2n-1}

(2)

\frac{2n^2}{n-1}

(3) infinite (4)

n