For a nucleus, the volume \( V \) is proportional to \( A \), the mass number, given by:
\[ V = \frac{4}{3}\pi R^3, \]where the radius \( R \) of a nucleus is proportional to the cube root of its mass number \( A \):
\[ R = R_0 A^{1/3}. \]Thus, the volume \( V \) of a nucleus can be expressed as:
\[ V \propto A. \]Since \( A_2 = 4A_1 \), the ratio of volumes is:
\[ \frac{V_2}{V_1} = \frac{A_2}{A_1} = 4. \]The electric potential at the surface of an atomic nucleus \( (z = 50) \) of radius \( 9 \times 10^{-13} \) cm is \(\_\_\_\_\_\_\_ \)\(\times 10^{6} V\).
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: