Answer:
pressure is equal to the net amount of force acting per unit area. Dimensional Formulae of force is M1L1T-2 and of area is L2. Therefore Pressure's dimension can be obtained by calculating Force by Area. Dimensional formula of pressure difference is M1L-1T-2.
Explanation:
This happens because the gas inside tend to expand because its temperature gets higher.
This is why the balloon that is put in a freezer for too long tend to gets smaller, because the gas temperature that is inside the balloon decreases.
(you can try it at home)
It is related to the temperature of the gas.
Balance tubes by spacing them equally around the centrifuge and Always balance tubes with other tubes containing a same volume of liquid are right.
If you don't space them out equally, you will have a lot of broken glass to clean up...trust me. The same thing can happen if you don't have equal amounts of liquid in each tube, but it doesn't have to be exactly the same in every one.