Question

Q.3,4,5 plz ans it fast becuse there is test tomorrow plz

Answer 1

1)  At high altitudes, the atmospheric pressure is low, and as altitude increases pressure decreases. So if the pressure of atmosphere changes auddenly, the blood vessels on our body will burst due to pressure of the blood and other fluids inside.It's due to the low pessure there.
b)  For sharp knife force is applied on a small region. While for blunt knife though force is same but is being applied on a larger area. So the pressure from the sharper one is higher
c)  because of gravity