The reactions with \( \text{Ag}^+ \) ions produce different colored precipitates depending on the halide present:
\[ \text{Ag}^+ + \text{I}^- \rightarrow \text{AgI} \quad (\text{Yellow ppt.}) \]
\[ \text{Ag}^+ + \text{Cl}^- \rightarrow \text{AgCl} \quad (\text{White ppt.}) \]
\[ \text{Ag}^+ + \text{Br}^- \rightarrow \text{AgBr} \quad (\text{Pale yellow ppt.}) \]
Since a pale yellow precipitate was obtained, it indicates the presence of \( \text{Br}^- \) ions.
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: