Needing explaining ! (2 pics attached)

#28

Fluid always flow from higher pressure to lower pressure so as we can see the figure liquid is coming out of the spray bottle so it clearly shows that the pressure outside the tube will be lower than the pressure inside the tube.

#29

Momentum is defined as product of mass and its velocity

so here we will have

here we have

so we will have

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.