Deimos, a moon of mars, is about 12 km in diameter; it has a mass of 2 x 1015 kg. with what speed would you have to throw a baseball on deimos
so that it would go into orbit and return to you so you could catch it?
5.8 m/s
4.7 m/s
2.2 m/s
3.4 m/s

V = 4.7 m/s

Explanation:

Given,

The diameter of Mar's moon, Deimos, D = 12 Km

                             Radius, R = D/ 2 = 12 /2 = 6 Km

                                                                     = 6000 m

The mass of the moon, m = 2 x 10¹⁵ Kg

in order to catch a baseball after orbiting the moon, it should be thrown with a velocity equal to the orbital velocity at that surface.

The orbital velocity at surface is given by,

                                            V = √(GM/R)  m/s

Substituting the given values in the above equation,

                                            V = √(6.673 x 10⁻¹¹ x 2 x 10¹⁵ / 6000)

                                                = 4.7 m/s

Hence, the baseball should be thrown with a velocity that would return after orbiting is, V = 4.7 m/s