NAME: ______PERIOD ______
PHYSICS 2 FLUID MECHANICS
1. Water is flowing with a speed of 9.0 m/s through a pipe of diameter 10 cm. The pipe widens to 30 cm as it goes up an 8.0 m step, as shown in the figure above.
If the pressure at point A is 2.0 x 105 Pa, what is the pressure at point B ?
(The density of water is 1.0 x 103 kg/m3.)
(A) 1.2 x 105Pa
(B) 1.6 x 105Pa
(C) 2.4 x 105Pa
(D) 3.2 x 105P
2. The figure above represents a portion of a blood vessel with circular cross sections. The segment
on the left has diameter 1.6 mm, and each of the segments on the right has diameter 0.4 mm.
Assume the blood can be treated as an ideal fluid. If blood enters the segment on the left with
speed v, at what speed does the blood leave the segments on the right?
(A) 2 v
(B) 4 v
(C) 8 v
(D) 16 v
3. A block is submerged in a container of liquid and held under the surface of the liquid by a string connected to the bottom of the container, as shown in the figure above. The tension in the string is not zero. How does the buoyant force FB exerted by the liquid on the block compare to the block’s weight w ?
(A) Fb < w
(B) Fb = w
(C) Fb > w
(D) Either FB < w or FB > w, depending on the density of the liquid.
4. An ideal fluid is flowing with a speed of 12 cm/s through a pipe of diameter 5 cm. The pipe splits into three smaller pipes, each with a diameter of 2 cm. What is the speed of the fluid in the smaller pipes?
(A) 4 cm/s
(B) 12 cm/s
(C) 25 cm/s
(D) 75 cm/s
5. Two samples of ideal gas in separate containers have the same number of molecules and the same temperature, but the molecular mass of gas X is greater than that of gas Y. Which of the following correctly compares the average speed of the molecules of the gases and the average force the gases exert on their respective containers?
Average Speed
of Molecules Average Force on Container
(A) Greater for gas X Greater for gas X
(B) Greater for gas X The forces cannot be compared without
knowing the volumes of the gases.
(C) Greater for gas Y Greater for gas Y
(D) Greater for gas Y The forces cannot be compared without
knowing the volumes of the gases.
Three different gas samples that have the same number of molecules and are at room temperature are kept at different pressures. A lab technician has determined the molecular mass of each gas and recorded the pressure and molecular mass of each sample in the table below.
Gas Molecular Mass (u) Pressure (*100 kPa)
X 2.0 6.0
Y 4.0 12
Z 40 1.0
6. Which of the following ranks the density ρ of the gas samples?
(A) ρ X = ρY > ρZ
(B) ρY > ρ Z > ρX
(C) ρZ > ρX = ρY
(D) ρZ > ρY > ρX
7. Planes fly be creating unequal pressure above and below the wing due to the speed of the air running by the wing which creates lift. Which scientist created the formula for this.
- Archimedes b. Einstein c. Bernoulli’s d. Pascal
8.
9.
10.
FREE RESPONSE
11.
12.
13.