The escape velocity form the earth surface in km S-1 is____________________?
A. 4.2 km S-1
B. 7.5 km S-1
C. 9.5 km S-1
D. 1.1 km S-1
A. 4.2 km S-1
B. 7.5 km S-1
C. 9.5 km S-1
D. 1.1 km S-1