Explain why an object when thrown in the air or slid across the ground doesn't travel forever

Gravity and friction inhibit the motion of the object, respectively

We often think of the air as "nothing" but in reality, there is always something there. It is so light that we often don't notice it, but the reason it still slows things down is the same as why something slid across the ground doesn't go forever - friction. You can feel how much the air pulls and pushes if you stick your hand out the window of a car or ride on a roller coaster. In each of these cases you will feel a force pushing you back. In reality, you are the one pushing through the air.

For cyclohexane compounds drawn in a chair conformation:   -axial bonds are vertical  -equatorial bonds are parallel to two bonds within the ring.  thus, as i assume the chair conformation is drawn:   -the x group is in an axial position, as are the five other vertical bonds.  -three axial bonds are on the top face of the ring  -the other three axial bonds are on the bottom face  the position of the second substituent on each ring carbon is equatorial.  gauche groups must be on an adjacent carbon such as carbon 6 and carbon 2, and also gauche groups are rotated by 60 degrees relative to each other.  drawing the newman projections for c1–c2 and c1–c6 aids in visualizing the groups that are gauche to the y group on c1.  click this link and watch some academic videos that may you more understand the topic