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Consider a block that is to be lifted by a wedge. As the wedge slides under the block, the block slides up the sloped side of a wedge. This lifts the weight F B of the block. The horizontal force F A needed to lift the block is obtained by considering the velocity of the wedge v A and the velocity of the block v B. If we assume the wedge does ...
A block and tackle [1] [2] or only tackle [3] is a system of two or more pulleys with a rope or cable threaded between them, usually used to lift heavy loads. The pulleys are assembled to form blocks and then blocks are paired so that one is fixed and one moves with the load.
The ideal mechanical advantage of the block and tackle is equal to the number of sections of the rope that support the moving block. In the diagram on the right, the ideal mechanical advantage of each of the block and tackle assemblies [7] shown is as follows: Gun tackle: 2; Luff tackle: 3; Double tackle: 4; Gyn tackle: 5; Threefold purchase: 6
When George Simpson became the first person to run 9.4 seconds for the 100-yard dash in 1930, his record was disallowed because he used starting blocks. [3] Wood was the first material used, with some tracks having permanently-placed wooden starting blocks as built-in structures at the start line.
The first nine blocks in the solution to the single-wide block-stacking problem with the overhangs indicated. In statics, the block-stacking problem (sometimes known as The Leaning Tower of Lire (Johnson 1955), also the book-stacking problem, or a number of other similar terms) is a puzzle concerning the stacking of blocks at the edge of a table.
A Jacob's ladder (also magic tablets, Chinese blocks, and klick-klack toy [1]) is a folk toy consisting of blocks of wood held together by strings or ribbons. When the ladder is held at one end, blocks appear to cascade down the strings. This effect is a visual illusion which is the result of one
Wheelchair ramp, Hotel Montescot, Chartres, France Demonstration inclined plane used in education, Museo Galileo, Florence.. An inclined plane, also known as a ramp, is a flat supporting surface tilted at an angle from the vertical direction, with one end higher than the other, used as an aid for raising or lowering a load.
Wooden boards are the most common breaking item in most martial arts, Individual boards used may range from nominal sizes as small as 6 in × 12 in × 1 in (152 mm × 305 mm × 25 mm) to as large as 12 in × 12 in × 1 in (305 mm × 305 mm × 25 mm) (a board with a nominal thickness of 1″ has an actual thickness of .75 in (19 mm)).