Consider 3rd orbit of He+ (Helium), using non-relativistic approach, the speed of electron in this orbit will be [given K=9×109 constant, Z = 2 and h(Planck’s Constant) = 6.6×10−34 J s]
1.46 × 106 m/s
v=14πε∘2πzε2nh
substituting the values, we get
v=1.46×106m/s