Answer:
(Option B)
Explanation:
The absolute pressure of the air-filled tank is:


Answer:

Explanation:
For pressure gage we can determine this by saying:
The closed tank with oil and air has a pressure of P₁ and the pressure of oil at a certain height in the U-tube on mercury is p₁gh₁. The pressure of mercury on the air in pressure gauge is p₂gh₂. The pressure of the gage is P₂.

We want to work out P₁-P₂: Heights aren't given so we can solve it in terms of height: assuming h₁=h₂=h

I say the answers is A but if you mean ventilation in the area of the room then answer B
Answer:
lubricating all moving parts in the engine
Explanation:
like the pistons, pushrods, and the crank