Página web multimedia, destinada al primer ciclo de ESO, con alto grado de interactividad debido al uso de applets
de Java que simulan en tiempo real el funcionamiento de los diferentes
mecanismos básicos basados en las variables de entrada introducidas por
el usuario.
Página web relacionada con los contenidos de Mecánica vistos en primer
ciclo de ESO. Divide los contenidos en seis apartados: máquinas,
operadores, mecanismos, organización, ejercicios e imprenta.
For part of the physics curriculum at Plano West, the students had to
build bridges out of nothing but paper, tape, and glue. This bridge held
1,071 lbs (485.79 Kg) after initially breaking the hook that held the weights at
800 lbs the day before. Details of the bridge: There are 6 compression members, each made of 7 sheets of paper; One V-shaped tension structure made of 20 sheets paper, layered and glued so that it would remain tight and flat; The base is made of 20 sheets paper, including the roadway; The loading zone and corner enforcements made of cut rolled members of 4 sheets thick; The paper nails used to pin all the joints total to about 1.5 sheets; One pack of J-B Weld glue (for all joints), used about 60%; A four-pack of super glue (for paper nails and final touches); One quart of wallpaper glue, used about 20% of it; In total, it amounted to about 90 sheets of paper, with a final weight of 493 grams.
The bridge broke on one of the compression members, but all of the joints are still intact. The hole in the loading zone is off center a bit, stressing that one compression member more than the others. It could improve a few hundred pounds if changes were made: The loading hole is drilled better in the center.
all four side members have 2 more sheets of paper (the two top members
remain same) while the V-shaped tension structure & the base could
be reduced by 4 sheets paper each.
Thornton-Tomasetti Engineers along with Evergreen Consulting Engineering designed a 660 tonnes (728 short tons)steel pendulum that serves as a tuned mass damper.
Suspended from the 92nd to the 87th floor, the pendulum sways to offset
movements in the building caused by strong gusts. Its sphere, the
largest damper sphere in the world, consists of 41 circular steel
plates, each with a height of 125 mm (4.92 in) being welded together to
form a 5.5 m (18 ft) diameter sphere.Another two tuned mass dampers, each weighing 6 tonnes (7 short tons),sit at the tip of the spire. These prevent damage to the structure due to strong wind loads.
[from wikipedia}
BUILDING BIG :BRIDGES BASICS
There are more than half a million bridges in the United States, and
you rely on them every day to cross obstacles like streams, valleys, and
railroad tracks. But do you know how they work? Or why some bridges are
curved while others are straight? Engineers must consider many things
-- like the distance to be spanned and the types of materials available
-- before determining the size, shape, and overall look of a bridge.
Since ancient times, engineers have designed three major types of bridges to withstand all forces of nature.
