1.gravitavtional pull pulls us down towards the ground
2.it exist so we do not float around
3.do not know how to solve 3( hope this help:)
A covalent bond forms when two or more valence electrons are attracted by the positively charged nuclei of two atoms and thus are shared between both atoms.
Given,
The initial inside diameter of the pipe, d₁=4.50 cm=0.045 m
The initial speed of the water, v₁=12.5 m/s
The diameter of the pipe at a later position, d₂=6.25 cm=0.065 m
From the continuity equation,

Where A₁ is the area of the cross-section at the initial position, A₂ is the area of the cross-section of the pipe at a later position, and v₂ is the flow rate of the water at the later position.
On substituting the known values,

Thus, the flow rate of the water at the later position is 5.99 m/s
Transverse Waves: Displacement of the medium is perpendicular to the direction of propagation of the wave. ... Longitudinal Waves: Displacement of the medium is parallel to the direction of propagation of the wave.