Since that is not far enough, you consult a friend who calculates (correctly) the minimum speed needed as vmin = 11068 m/s. if you leave the surface of the earth at this speed, how fast will you be moving at the surface of the moon? hint carefully write out an expression for the potential and kinetic energy of the ship on the surface of earth, and on the surface of moon. be sure to include the gravitational potential energy of the earth even when the ship is at the surface of the moon!

2.456 km /s

Explanation:

Let the mass of the object thrown be unity.

Potential energy due to attraction of the earth on the earth

=  - GM/R

(6.6 x 10⁻¹¹ x 5.972 x 10²⁴) / 6371 x 10³

= - 6.18 x 10⁷ J

Kinetic energy due to velocity of the object

= .5 x ( 11068 )²

= 6.1 x 10⁷ J

Total energy

= - .08 x 10⁷ J

Potential energy due to attraction of the moon on the moon

=  - GM/R

(6.6 x 10⁻¹¹ x 7.347 x 10²²) / 1737 x 10³

= - .279 x 10⁷ J

Potential energy due to attraction of the earth  on the moon

=  - GM/d where d is distance from the earth to the moon

=  (6.6 x 10⁻¹¹ x 5.972 x 10²⁴) / 3.84 x 10⁸

= -.1026 x 10⁷ J

Total potential energy

= -.3816 x 10⁷ J

If v be the velocity on the moon

total energy on the moon

= -.3816 x 10⁷  + .5 v² = -  .08 x 10⁷

.5 x v² = ( .3816 - .08 ) x 10⁷

v² = 6.032 x 10⁶

v = 2.456 x 10³m /s

= 2.456 km /s

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me