The mass and the diameter of a planet are three times the respective values for the Earth. The period of oscillation of a simple pendulum on the Earth is 2 s. The period of oscillation of the same pendulum on the planet would be:\\
(1) $\frac { \sqrt { 3 } } { 2 } \mathrm {~s}$\\
(2) $\frac { 2 } { \sqrt { 3 } } \mathrm {~s}$\\
(3) $\frac { 3 } { 2 } s$\\
(4) $2 \sqrt { 3 } \mathrm {~s}$