Question

Q.3. Give reasons for the following:
a) Nose starts bleeding on high mountains.
b) Two holes are made in sealed tin can to take out oil from it.
c) A balloon filled with hydrogen rises to a certain height.
d) An egg sinks in fresh water but float in a strong salt solution
e) Cutting tools have sharp edge.

Answer 1

e) cutting tools have sharp edge because to cut anything we need something sharp not bold . So this is the reason for the given above.

c) When we fill hydrogen gas in a balloon it raises high because our air has many layers at a certain layer the wind contains hydrogen .

Answer 2

Answer:

Explanation:a) as altitude increases, the availability of oxygen decreases, making the air thinner and drier. The dryness can cause the nose to bleed.

B)through the second hole(usually on the top) ,air pressure is applied on oil the tin can which forces it out of the other hole.

C) hydrogen is lighter than other gases that constitute the atmosphere.

D) Because the density of the egg is higher than the density of tap water, so it sinks. ... When enough salt is added to the water, the saltwater solution's density becomes higher than the egg's, so the egg will then float

E) pressure is inversely proportional to area. So cutting objects have less area so they can apply more pressure and cut through things easily