A bell bollard is a style of bollard designed to deflect vehicle tires. The wheel mounts the lower part of the bollard and is deflected by its increasing slope. Such bollards are effective against heavy goods vehicles that may damage or destroy conventional bollards or other types of street furniture. A variant on the bell bollard is the Martello bollard, its sloped shape inspired by the profile of historic Martello towers. Removable bollards Bollards may be hinged at ground level, allowing them to be folded flat to permit vehicles to drive over them.
In stoichiometry calculations, we assume that reactions run to completion. However, when a chemical reaction is carried out in a closed vessel, the system achieves equilibrium. Equilibrium occurs when there is a constant ratio between the concentration of the reactants and the products. Different reactions have different equilibria. Some may appear to be completely products, however, all reactions have some reactants present.
Static equilibrium is a form of equilibrium that occurs when an object is at rest. Static refers to the object being motionless while equilibrium refers to the object either having no net forces acting upon it or having all of its net forces balanced.