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32. Question: Why does a balloon flled with hydrogen rise in the air?

Answer: Weight o hydrogen is less than the weight o air displaced by it. In

balloons hydrogen is normally flled because it is lighter than air.

33. Question: Why do we lean orward while climbing a hill?

Answer: In order to eeps the !ertical line passing through our centre o

gra!ity always between our eet" which is essential to attain e#uilibrium or

stability.

3$. Question: Why does smoe curl up in the air?

Answer: %moe contains hot gases which being lighter in weight" ollows a

cur!ed path because o the eddy currents that are set up in the air.