Atomic Oxygen Is One of the Major Constituents of the Upper

Atomic oxygen is one of the major constituents of the upper atmosphere in the region of low Earth orbit (LEO) . LEO is approximately 150 miles $( 240 \mathrm {~km} )$ above the surface of the Earth. The radius and mass of the Earth are $6.4 \times 10 ^ { 6 } \mathrm {~m}$ and $5.98 \times 10 ^ { 24 } \mathrm {~kg}$ . The mass of atomic oxygen is $16 \times \left( 1.67 \times 10 ^ { - 27 } \mathrm {~kg} \right)$ . The kinetic energy at which the atomic oxygen strikes the surface of the space shuttle is

A) 8.0 $\times$ 10^-18 J.
B) 8.0 $\times$ 10^-19 J.
C) 8.0 $\times$ 10^-20 J.
D) 8.0 $\times$ 10^-21 J.