A body of mass 2 kg moving on a horiontal surface with apeed `v_(i)=1ms^(-1)` enters a rough patch ranging from `x=0.5m` to `x=1.5m.` If the body comes to rest after pussing the patch, then find the retarding force on the body.

Explanation

W-E theorem,
`f_(r),s=1/2m(v_(f)^(2)-v_(i)^(2))`
`W=K_(f)-K_(i)`
`f_(r)(1.5-0.5)=-1/2xx2xx1^(2)`
`f_(r)=-1N`