Friction and air resistance are two big hurdles that make it harder for things to speed up when they move.

1. Friction:

   • This force works against moving objects, making them go slower.
   • It depends on what the surface is like and how heavy the object is.

2. Air Resistance:

   • This force gets stronger as things go faster. The quicker you go, the more air pushes against you.
   • It also depends on the shape and size of the object.

Solutions:

• You can cut down on friction by using things like oil or grease.
• To help with air resistance, shape objects so they move through the air easier.

In the end, understanding these forces is really important for guessing how things will move.