Earth has mass \( 8 \) times and radius \( 2 \) times that of a planet. If the escape from the earth is \( 11.2 \,\text{km/s} \), the escape velocity in km/s from the planet will be:
\( 8.4 \)
\( 5.6 \)
\( 11.2 \)
\( 2.8 \)