1. Give reasons for the following:
(1) Trucks and lorries have broad or double tyres.
(2) Astronauts wear special suits in space.
(3) People experience nasal bleeding at high altitudes.
(4) We do not feel air pressure although air exerts pressure in all directions.
Answers
Answer:
(1) Trucks and lorries have broad or double tyres.
REASON : The tyres are broader because this increases the area of contact with the ground, thus reducing the pressure exerted on the ground and and the tyres dont burst.
(2) Astronauts wear special suits in space.
REASON : Astronauts are trained to go into outer space. They usually wear a special suit called a spacesuit. If Astronauts need to survive in space, they have to wear a spacesuit. The suits protect astronauts from getting too hot or cold. A spacesuit protects astronauts from those extreme temperatures. Spacesuits also supply astronauts with oxygen to breathe while they are in the vacuum of space. They contain water to drink during spacewalks. They protect astronauts from being injured from impacts of small bits of space dust.
(3) People experience nasal bleeding at high altitudes.
REASON : We know that atmospheric pressure decreases with high altitude. So, at higher altitude atmospheric pressure is lower compared to the pressure at the surface. At higher altitudes the blood pressure inside our body is more than the atmospheric pressure which forces the blood to ooze out from openings like the nose. Hence the nose bleeding.
(4) We do not feel air pressure although air exerts pressure in all directions.
REASON : We don’t feel the atmospheric pressure due to an absence of a pressure difference between the external air and the air that’s inside our body, which we’ll call ‘internal air’.