Among the given elements: - Eu (Europium), Er (Erbium), Tb (Terbium), Yb (Ytterbium), and Lu (Lutetium) all belong to the lanthanoid series. Cm (Curium) belongs to the actinide series.
Hence, the number of elements that do not belong to lanthanoids is 1 (Cm).
A body of mass 1000 kg is moving horizontally with a velocity of 6 m/s. If 200 kg extra mass is added, the final velocity (in m/s) is: