Mastering Physics 14

the same height

A one-inch depth of sand is poured onto the cap on each arm. (Figure 2) After the caps have moved (if necessary) to reestablish equilibrium, is the right cap higher, lower, or the same height as the left cap? higher lower the same height

20 g

A rectangular wooden block of weight W floats with exactly one-half of its volume below the waterline. Masses are stacked on top of the block until the top of the block is level with the waterline. This requires 20 g of mass. What is the mass of the wooden block? 40 g 20 g 10 g

more dense

A rectangular wooden block of weight W floats with exactly one-half of its volume below the waterline. The wooden block is removed from the water bath and placed in an unknown liquid. In this liquid, only one-third of the wooden block is submerged. Is the unknown liquid more or less dense than water? more dense less dense

0.50 g/cm3

A rectangular wooden block of weight W floats with exactly one-half of its volume below the waterline. The density of water is 1.00 g/cm3. What is the density of the block? 2.00 g/cm3 between 1.00 and 2.00 g/cm3 1.00 g/cm3 between 0.50 and 1.00 g/cm3 0.50 g/cm3 The density cannot be determined.

ρunknown = 1.5g/cm3

A rectangular wooden block of weight W floats with exactly one-half of its volume below the waterline. The wooden block is removed from the water bath and placed in an unknown liquid. In this liquid, only one-third of the wooden block is submerged. What is the density of the unknown liquid ρunknown? Express your answer numerically in grams per cubic centimeter.

W

A rectangular wooden block of weight W floats with exactly one-half of its volume below the waterline. What is the buoyant force acting on the block? 2W W 1/2W The buoyant force cannot be determined.

psep<pmix

Assume that before separation, the pressure at the bottom of the milk bottle is pmix. How does the pressure at the bottom of the milk bottle after separation, psep, compare to pmix? For simplicity, you may assume that the weight and density of the cream is negligible compared to that of the milk. psep>pmix psep=pmix psep<pmix

wsep=wmix

Assume that before separation, the weight of the milk bottle's contents (mixed milk and cream) is wmix. How does the combined weight of the milk and cream after separation, wsep, compare to wmix? wsep>wmix wsep=wmix wsep<wmix

v2 = v1A1/A2

Because the fluid is assumed to be incompressible and mass is conserved, at a particular moment in time, the amount of fluid that flows into the pipe must equal the amount of fluid that flows out. This fact is embodied in the continuity equation. Using the continuity equation, find the velocity v2 of the fluid flowing out of the right end of the pipe.

Q1 = v1A1

Find Q1, the volume of fluid flowing into the pipe per unit of time. This quantity is also known as the volumetric flow rate.

100

For parts D - F imagine that plaque has grown to a 90% blockage. By what factor does the kinetic energy per unit of blood volume increase as the blood passes through this blockage?

10

For parts D - F imagine that plaque has grown to a 90% blockage. Relative to its initial, healthy state, by what factor does the velocity of blood increase as the blood passes through this blockage?

Δp = 1000 Pa

For parts D - F imagine that plaque has grown to a 90% blockage. What is the magnitude of the drop in blood pressure, Δp, as the blood passes through this blockage? Use K0 as the normal (i.e., unblocked) kinetic energy per unit volume of the blood.

WILL ADD AFTER ITS OPEN FOR REDO

ITEM 1

4.0 kg

If a 1.0-kg-mass block is on the left cap, how much total mass must be placed on the right cap so that the caps equilibrate at equal height?

Speed

If you are shown a picture of streamlines in a flowing fluid, you can conclude that the __________ of the fluid is greater where the streamlines are closer together.

It decreases by about 250 Pa.

Imagine that plaque has narrowed an artery to one-fifth of its normal cross-sectional area (an 80% blockage). As the blood passes through this blockage, what happens to the blood pressure? It increases by about 250 Pa. It increases by about 41 Pa. It stays the same. It decreases by about 41 Pa. It decreases by about 250 Pa.

25

Imagine that plaque has narrowed an artery to one-fifth of its normal cross-sectional area (an 80% blockage). By what factor does the kinetic energy per unit of blood volume change as the blood passes through this blockage? 25 5 1

5v0

Imagine that plaque has narrowed an artery to one-fifth of its normal cross-sectional area (an 80% blockage). Compared to normal blood flow velocity, v0, what is the velocity of blood as it passes through this blockage? 80v0 20v0 5v0 v0/5

3.0 Kg

The locations of the two caps at equilibrium are now as given in this figure. (Figure 4) The dashed line represents the level of the water in the left arm. What is the mass of the water located in the right arm between the dashed line and the right cap?

higher

The sand is removed and a 1.0-kg-mass block is placed on each cap. (Figure 3) After the caps have moved (if necessary) to reestablish equilibrium, is the right cap higher, lower, or the same height as the left cap? higher lower the same height

d = L(ρ1−ρ3)/(ρ2−ρ3)

What is the distance d between the top of the wood cube (after it has come to rest) and the interface between the oil and water? Express your answer in terms of quantities given in the problem introduction.