A bullet of mass 0.1 kg is fired on a wooden block to pierce through it, but it stops after moving a distance of 50 cm into it. If the velocity of…

A bullet of mass $\displaystyle 0.1$ kg is fired on a wooden block to pierce through it, but it stops after moving a distance of $\displaystyle 50$ cm into it. If the velocity of bullet before hitting the wood is $\displaystyle 10 \mathrm{~m} / \mathrm{s}$ and it slows down with uniform deceleration, then the magnitude of effective retarding force on the bullet is '$\displaystyle x$' $\displaystyle \mathrm{N}$.The value of ' $\displaystyle x$ ' to the nearest integer is \_\_\_\_.