Today is the Longest Day of the Year (Photos of the Midnight Sun) June 21 gets the prize as the longest day of the year 2013 in Iceland. Whatâs more, summer seems to be arriving in ReykjavÃ­k. Last night people were waiting to see the midnight sun set, well at midnight in ReykjavÃ­k. The air was calm and clean and so were the people who sat on the shore.
Definition of airfoil. : a body (such as an airplane wing or propeller blade) designed to provide a desired reaction force when in motion relative to the surrounding air.
Air is a physical substance which has weight. It has molecules which are constantly moving. Air pressure is created by the molecules moving around. Moving air has a force that will lift kites and balloons up and down. Air is a mixture of different gases; oxygen, carbon dioxide and nitrogen. All things that fly need air. Air has power to push and pull on the birds, balloons, kites and planes.