Changes

===About Tensions===

: [[Tension]] is a [[Contact Force|contact force]] because it exists within a [[material]].

: [[Tension]] is often used to describe the [[force]] in a [[cable]] or wire.

: [[Tension]] is caused by an [[Equilibrium Pair|equilibrium pair]] of [[force]]s which is a [[force]] at each end of the [[object]] acting with the same [[magnitude]] but in opposite directions.