An earth-sized planet is found to be 9 light-years away from earth. If you are travelling in a spaceship with speed $22 \mathrm{km}/\mathrm{s}$, then how much time will you take to reach that plant?

State some applications of artificial satellites.

Note: In book exercise the question was given as applications of natural satellites but as the class book has applications of only artificial satellites given so, the question has been changed to applications of artificial satellites.