Some things that causes friction between surfaces is a bike on a rocky road. The<span> action of one surface or object rubbing against another causing friction. Im not really sure if I helped But yeah..</span>
The speed of the carts descent will increase? Not quite sure what you’re asking.
"<span>Same </span>fluid<span> can behave as compressible and </span>incompressible<span> depending upon flow conditions. ... The most common </span>example<span> of compressible flow concerns is the flow of gases (at low velocities), while the flow of </span>liquids<span> may frequently be treated as </span>incompressible<span>(under low pressure)." -Google</span>
Function of insulators is protection against sound or electric current or ,heat based on the type of insulators.
They use in wires (plastic)
Use in making soundproof rooms
Thermal insulators are use in making water bottles. Keep the water warm