Why do bags and suitcases have broad (wide) handles?

Explain the pressure-measuring device at any point in a fluid in short.

When two metals of equal volume are mixed,the relative density of the mixture is $4$. When equal masses of these two metals are mixed,the relative density of the mixture is $3$. What are the relative densities of the two metals?

In the arrangement shown, both the vessels $A$ and $B$ are identical, but the amount of water in $B$ is double that in $A$. The vessels are closed by identical leak-proof pistons at the same height. The pistons are connected to the ends of a lever arm. There is no friction between the pistons and the container walls. The system is in equilibrium in the situation shown. Now, the valve in the horizontal tube connecting both the vessels is opened. In which direction will the water flow through the tube?

The pressure at the bottom of a tank of water is $3P$,where $P$ is the atmospheric pressure. If the water is drawn out until the level of water is lowered by one-fifth,the pressure at the bottom of the tank will now be:

Define pressure. Give the $SI$ and $CGS$ unit of pressure.