Aira Force

Coordinates: 54°34′35″N 2°55′51″W / 54.576303°N 2.930905°W / 54.576303; -2.930905

Aira Force is a waterfall in the English Lake District, near the village of Watermillock in the county of Cumbria. The site of the waterfall is owned by the National Trust.

Description

The stream which flows over the waterfall is Aira Beck, which rises on the upper slopes of Stybarrow Dodd at a height of 720 metres (2,362 ft) and flows north-easterly before turning south, blocked by the high heather-covered slopes of Gowbarrow Fell. It turns south on its eight-kilometre journey to join Ullswater, at a height of 150 metres (492 ft). One kilometre before entering the lake, the beck makes the 20 metres (66 ft) leap down a rocky and steep sided ravine at the falls known as Aira Force. The water falls approximately 22 metres (72 ft) to a rocky pool, from where the beck continues through a shallow valley to the lake.

The river name Aira is derived from Old Norse eyrr, a gravel bank, and Old Norse á, a river, hence The river at the gravel bank, a reference to Aira Point, a gravelly spit where the river enters Ullswater. The Old Norse word fors, waterfall, has been adopted into several northern English dialects and is widely used for waterfalls, with the English spelling 'Force'. Thus, The waterfall on gravel-bank river.

Lake District

The Lake District, also known as The Lakes or Lakeland, is a mountainous region in North West England. A popular holiday destination, it is famous for its lakes, forests and mountains (or fells) and its associations with the early 19th century writings of William Wordsworth and the other Lake Poets.

Historically split between Cumberland, Westmorland and Lancashire, the Lake District is now entirely in Cumbria. All the land in England higher than 3,000 ft (910 m) above sea level lies within the National Park, including Scafell Pike, the highest mountain in England. It also contains the deepest and longest lakes in England, Wastwater and Windermere.

Lake District National Park

The Lake District National Park includes nearly all of the Lake District, though the town of Kendal and the Lakeland Peninsulas are currently outside the park boundary.

The area, which was designated a national park on 9 May 1951 (less than a month after the first UK national park designation — the Peak District), is the most visited national park in the United Kingdom with 15.8 million annual visitors and more than 23 million annual day visits, the largest of the thirteen national parks in England and Wales, and the second largest in the UK after the Cairngorms. Its aim is to protect the landscape by restricting unwelcome change by industry or commerce. Most of the land in the park is in private ownership, with about 55% registered as agricultural land. Landowners include:

Force

In physics, a force is any interaction that, when unopposed, will change the motion of an object. In other words, a force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate. Force can also be described by intuitive concepts such as a push or a pull. A force has both magnitude and direction, making it a vector quantity. It is measured in the SI unit of newtons and represented by the symbol F.

The original form of Newton's second law states that the net force acting upon an object is equal to the rate at which its momentum changes with time. If the mass of the object is constant, this law implies that the acceleration of an object is directly proportional to the net force acting on the object, is in the direction of the net force, and is inversely proportional to the mass of the object

Related concepts to force include: thrust, which increases the velocity of an object; drag, which decreases the velocity of an object; and torque, which produces changes in rotational speed of an object. In an extended body, each part usually applies forces on the adjacent parts; the distribution of such forces through the body is the so-called mechanical stress. Pressure is a simple type of stress. Stress usually causes deformation of solid materials, or flow in fluids.