Given The mass of the bullet, m=0.1kg The initial velocity of the bullet before hitting the wooden, u=10m∕s The final velocity of the bullet after hitting the wooden, v=0 The distance travelled by the bullet before coming to the rest, s=50cm Using the equation of the motion, v2−u2=2as ⇒02−(10)2=2a(0.50) ⇒a=−100m∕s2 The uniform retardation of the bullet is 100m∕s2 The magnitude of the effective retarding force on the bullet, F=maF=0.1(−100) F=−10N Hence, the value of x to the nearest integer is 10 .