A needle placed carefully on water, however, can be supported by the surface tension-the liquid responds in a way similar to a stretched membrane. Try it at home-see what you can get to float on water. One way to think of surface tension is in terms of energy. The larger the surface, the more energy there is.
The Airedale is the largest of the British terriers. They weigh 20â30 kilograms (44â66 lb) in fit condition and have a height at the withers of 58â61 centimetres (23â24 in) for males, with females slightly smaller. The American Kennel Club standard specifies a very slightly smaller dog.
American Staffordshire Terrier. American Staffordshire Terrier. Another type of pitbull, somewhat larger than the APT, is the American Staffordshire. This dog weighs 65 to 90 pounds and is built similarly, but has a thicker coat. The build is square and muscular, and like American Pitbull Terriers, Staffies have a friendly and loyal nature.