Question

Read the passage carefully:-

ANIMAL BUILDERS

Animals are great builders, using simple materials but employing sound engineering

principles. Man has long used suspension bridges made of ropes of steel and concrete, which

bear loads in tension. The webs of spider provide the most vivid examples of animal

structures built entirely in tension. Spider web silk is so strong that many species of birds use

it to build their nests. It has a stiffness index which is 30 times less than that of steel, yet

has a tensile strength one and a half times as much as that of steel. Unlike steel, silk

stretches to more than twice its original length before breaking. These qualities, it is now

known, are owing to silk being a protein polymer composed of crystalline regions

interspersed with regions of randomly arranged chains.

Beavers are natural engineers. They use tree branches to construct dams, the divided end

being pressed into the walls; this apparently serves to collect stress from a broad area and to

focus it into a single trunk embedded in the substrate of the stream. The dams of the beaver

have an angle of 45degree on the downstream side. This enables the structure to resist the

lateral pressure of water acting upstream. aswer the following question briefly a). why animals are called building engineer b).why many species of birds use spider web for their nests c).what equates spider web silk to steel d).what is the stiffness index of spider web silk e).why the dams of beaver have an angle of 45° on downstream side f).who are beavers g). write the meaning of interspersed h). write the meaning of embedded

Answer 1

1. They are called building engineer because they use simple and natural things
2.spider web have silky and smooth fibres so birds use them to make there nest
4.the stiffness index of spider web is 30times less than steel
5.they have the 45°on downstream side as it enable the structure to resist the lateral pressure of wateracting up stream
6.beavers are the species of birds. They are also called natural engineer

Answer 2

Explanation:

what is the meaning of employing