A body travels uniformly a distance of (40.0±0.1) m in time (2.0±0.04)s. The velocity of the body is

V=St=402=20  ΔVv=ΔSs+Δtt⇒ΔV=V[ΔSs+Δtt]                                         =20[0.140+0.042]                                          =0.45                        ⇒V±ΔV=20±0.45