Answer:
Explanation:
First, we find the mass of the air originally in the tank.
Density is given as mass divided by volume. It is given as:

Therefore, mass is:

Density of air =
; Volume of the tank = 

The mass of the air initially in the tank is 7 kg.
After air is allowed to enter, the mass changes.
New density = 
The new mass will be:

We can now find the mass of air that has entered the tank:
Mass of air that entered tank = New mass of air - Original mass of air
M = 22.75 - 7.0 = 15.75 kg
The mass of air that entered the tank is 15.75 kg.
Answer:
Explanation:if you stretch the hose more tightly the speed of the pulse will reduce..
True I think I’m not sure?
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
