Download AP Physics Test - Fluids Name: 1) The figure above shows an object

AP Physics Test - Fluids
Name:
5) An underground water pump provides pressure for a
fountain in the lobby of a casino. The fountain shoots
straight upward, but the casino owner is dissatisfied
with the height of the stream. Which of the following
would increases the maximum height achieved by the
water?
1) The figure above shows an object of volume 0.01 m3
that is suspended from a scale in air, and then
submerged in a liquid of density 1,200 kg/m3. If the
reading on the scale is 200 N when the object is in air,
what will be the scale reading when the object is
submerged?
(A) 0 N (B) 80 N (C) 100 N (D) 120 N (E) 150 N
2) A large cylindrical tank of maple syrup is sealed with a
vacuum on top, and develops a small hole at a depth h
below the surface of the water, as shown above.
Assuming that atmospheric pressure is 100,000 Pa and
the density of maple syrup is 1,325 kg/m3, what is the
maximum possible depth of the hole that will result in
no syrup leaking out?
(A) 0.75 m (B) 7.5 m (C) 75 m
(D) Syrup will leak out, no matter how deep the hole.
(E) Syrup will not leak out, no matter how deep the hole.
3) An ice cube floats in a glass of blood so that 4/5 of it is
submerged. If B is the density of blood, then the
density of ice is
(A) B/4
(B) B/5
(C) 4B/5
(D) B (E) 5B/4
4) A closet serial killer is watering a garden with a hose of
cross-sectional area A. By placing his finger over the
end of the hose, he reduces the area to A/8. By what
factor does the exit velocity of the water multiply when
he does this?
(A) 1/64
(B) 1/8
(C) 1
(D) 8
(E) 64
I. Increase the pump pressure.
II. Bring the pump closer to the surface of the water.
III. Increase the cross-sectional area of the nozzle that
sprays the water.
(A) I only (B) II only (C) III only
(D) I and II (E) I and III
6) Each of the beakers shown above is filled to the same
depth h with liquid of density . Which of the following
ranks the beakers according to the pressure at the
bottom of the container, from least to greatest?
(A) I, III, II, IV
(D) IV, III, I, II
(B) I, IV, III, II
(C) II, III, IV, I
(E) Pressure is the same for each.
7) Which of the following statements is not true about
fluid pressure?
(A) For a fluid at rest, it increases in direct proportion
to the depth of the fluid.
(B) For a fluid at rest, differences in fluid pressure give
rise to buoyant force.
(C) It has units of J/m3.
(D) In a horizontal pipe, it is greatest where the fluid is
moving the fastest.
(E) It is a scalar.
8) A fluid with density  and speed v flows through a flat,
horizontal pipe system. If the cross-sectional area of the
pipe is doubled in a second section of the pipe, which
of the following represents the magnitude of the
pressure difference between the two sections of pipe?
(A) v2/4 (B) 3v2/8 (C) v2/2 (D) 3v2/4 (E) v2
9) An object is observed to float when placed in a fluid. Which of the following is true?
I. The density of the fluid is greater than the density of the object.
II. As it floats, the object will displace an amount of water having a mass equal to the mass of the object.
III. When completely submerged, the object will displace an amount of water having a volume equal to the volume of
the object.
(A) I only (B) I and II
(C) I and III
(D) II and III (E) I, II and III
10) In a hydraulic lift, a weight W sitting on a light platform of area A2 is held in place by a force F applied to a smaller area
A1. The two platforms are at the same height, as shown above. Which of the following is true?
(A) F = W
(B) F = W(A1/A2)
(C) F = W(A2/A1)
(D) F = A1/A2
(E) F = W(A2 – A1)
10) A sailboat at rest on a calm lake has its anchor dropped a distance of 4.0 m below the surface of the water. A rope of
negligible mass and volume suspends the anchor. The mass of the anchor is 50 kg, and its volume is 6.25 x 10-3 m3. The
density of water is 1000 kg/m3.
(a) On the dot below that represents the anchor, draw and label the forces (not components) that act on the anchor. (4 pts)
(b) Calculate the magnitude of the buoyant force acting on the anchor. If you need to draw anything other than what you
have shown in part (a) to assist in your solution, use the space below. DO NOT add anything to the figure in part (a).
(3 pts)
(c) Calculate the tension in the rope. If you need to draw anything other than what you have shown in part (a) to assist in
your solution, use the space below. DO NOT add anything to the figure in part (a). (3 pts)
(d) Suppose the rope is cut. Describe the resulting motion of the anchor, from the moment the rope is cut until the moment
just before the anchor strikes the ocean floor. Be specific and complete with your description, and make sure to use
proper physics terminology. (4 pts)
(e) The bottom of the boat is at a depth d below the surface of the water. Suppose the anchor is lifted back into the boat so
that the bottom of the boat is at a new depth d’ below the surface of the water. How does d’ compare to d?
____ d < d’
____ d < d’
____ d = d’
Justify your answer. (4 pts)
11) A drinking fountain projects water at an initial angle of 50° above the horizontal, and the water reaches a maximum
height of 0.150 m above the point of exit. Assume that air resistance is negligible.
(a) Calculate the speed at which the water leaves the fountain. (3 pts)
(b) The radius of the fountain’s exit hole is 4.0 x 10-3 m. Calculate the volume rate of flow of the water. (4 pts)
(c) The fountain is fed by a pipe that has a radius of 7.0 x 10-3 m and is 3.0 m below the fountain’s opening. The density
of water is 1.0 x 103 kg/m3. Calculate the pressure in the feeder pipe at this point. (5 pts)