IB Questionbank

Updates to Questionbank

User interface language: English | Español

Date	November 2018	Marks available	2	Reference code	18N.3.HL.TZ0.10
Level	Higher level	Paper	Paper 3	Time zone	0 - no time zone
Command term	Suggest	Question number	10	Adapted from	N/A

Question

A horizontal pipe is inserted into the cylindrical tube so that its centre is at a depth of 5.0 m from the surface of the water. The diameter D of the pipe is half that of the tube.

When the pipe is opened, water exits the pipe with speed u and the surface of the water in the tube moves downwards with speed v.

An ice cube floats in water that is contained in a tube.

The ice cube melts.

Suggest what happens to the level of the water in the tube.

[2]

a.

Outline why u = 4v.

[2]

b.i.

The density of water is 1000 kg m^–3. Calculate u.

[2]

b.ii.

Markscheme

ice displaces its own weight of water / OWTTE

OR

melted ice volume equals original volume displaced / OWTTE ✔

no change will take place ✔

a.

continuity equation says v × A₁ = u × A₂ ✔

«and» A₁ = 4A₂ ✔

«giving result»

b.i.

Bernoulli:

« $\frac{1}{2}\rho {v^2} + \rho gH + {P_{{\text{atm}}}} = \frac{1}{2}\rho {u^2} + 0 + {P_{{\text{atm}}}}$ » gives $\frac{1}{2} \times 1000 \times \frac{{{u^2}}}{{16}} + 1000 \times 9.8 \times 5.0 = \frac{1}{2} \times 1000 \times {u^2}$ ✔

u = 10.2 «m s^–1» ✔

Accept solving directly via conservation of energy.

b.ii.

Examiners report

[N/A]

a.

[N/A]

b.i.

[N/A]

b.ii.

Syllabus sections

Option B: Engineering physics » Option B: Engineering physics (Additional higher level option topics) » B.3 – Fluids and fluid dynamics (HL only)

Show 37 related questions

17N.3.SL.TZ0.11a.i: Identify the mechanism leading stars to produce the light they emit.
17N.3.SL.TZ0.11b.ii: Outline how the stellar parallax angle is measured.
18M.3.HL.TZ1.10c.ii:
Outline whether it is reasonable to assume that flow is laminar in this situation.
19M.3.HL.TZ1.10b.i: Outline why the speed of the gasoline at X is the same as that at Y.
17N.3.SL.TZ0.11b.i: Outline what is meant by a constellation.
17N.3.HL.TZ0.11a.i:
Using the graph, determine the buoyancy force acting on a sphere when the ethanol is at a temperature of 25 °C.
18M.3.HL.TZ1.10a:
State the difference in terms of the velocity of the water between laminar and turbulent flow.
18M.3.HL.TZ2.10b.i:
Estimate the Reynolds number for the fluid in your answer to (a).
18N.3.HL.TZ0.10b.i: Outline why u = 4v.
19M.3.HL.TZ2.13a:
Draw and label the forces acting on the sphere at the instant when it is released.
17M.3.HL.TZ1.9a:
Explain the origin of the buoyancy force on the air bubble.
17M.3.HL.TZ2.10a.ii:
On the diagram, draw an arrow to indicate the direction of this force.
17M.3.HL.TZ2.10a.i:
Estimate the magnitude of the force on the ball, ignoring gravity.
17N.3.SL.TZ0.11a.ii:
Outline why the light detected from Jupiter and Vega have a similar brightness, according to an observer on Earth.
17N.3.SL.TZ0.11b.iii:
Show that the distance to Vega from Earth is about 25 ly.
17N.3.HL.TZ0.11b:
The room temperature slightly increases from 25 °C, causing the buoyancy force to decrease. For this change in temperature, the ethanol density decreases from 785.20 kg m^–3 to 785.16 kg m^–3. The average viscosity of ethanol over the temperature range covered by the thermometer is 0.0011 Pa s. Estimate the steady velocity at which the 25 °C sphere falls.
17M.3.HL.TZ2.10b:
State one assumption you made in your estimate in (a)(i).
18N.3.HL.TZ0.10b.ii:
The density of water is 1000 kg m^–3. Calculate u.
16N.3.HL.TZ0.13b:
Water flows through a constricted pipe. Vertical tubes A and B, open to the air, are located along the pipe.

Describe why tube B has a lower water level than tube A.
17M.3.HL.TZ1.9b:
With reference to the ratio of weight to buoyancy force, show that the weight of the air bubble can be neglected in this situation.
18M.3.HL.TZ1.10b:
The water level is a height H above the turbine. Assume that the flow is laminar in the outlet pipe.

Show, using the Bernouilli equation, that the speed of the water as it enters the turbine is given by v = $\sqrt {2gH}$ .
19N.3.HL.TZ0.9a:
Explain why the levels of the liquid are at different heights.
19M.3.HL.TZ1.10b.ii:
Calculate the difference in pressure between X and Y.
20N.3.HL.TZ0.12a: State two properties of an ideal fluid.
20N.3.HL.TZ0.12c(iii):
Outline the effect on $Q$ of changing the oil to one with greater viscosity.
18M.3.HL.TZ1.10c.i:
Calculate the Reynolds number for the water flow.
20N.3.HL.TZ0.12c(i):
Determine the force exerted by the spring on the sphere when the sphere is at rest.
17M.3.HL.TZ1.9c:
Calculate the terminal speed.
20N.3.HL.TZ0.12b:
Determine the terminal velocity of the sphere.
16N.3.HL.TZ0.13a:
A solid cube of side 0.15 m has an average density of 210 kg m^–3.

(i) Calculate the weight of the cube.

(ii) The cube is placed in gasoline of density 720 kg m^–3. Calculate the proportion of the volume of the cube that is above the surface of the gasoline.
17N.3.HL.TZ0.11a.ii:
When the ethanol is at a temperature of 25 °C, the 25 °C sphere is just at equilibrium. This sphere contains water of density 1080 kg m^–3. Calculate the percentage of the sphere volume filled by water.
19N.3.HL.TZ0.9b:
The density of the liquid in the tube is 8.7 × 10²kg m^–3 and the density of air is 1.2 kg m^–3. The difference in the level of the liquid is 6.0 cm. Determine the speed of air at A.
19M.3.HL.TZ2.13b: Explain why the sphere will reach a terminal speed.
19M.3.HL.TZ2.13c:
The weight of the sphere is 6.16 mN and the radius is 5.00 × 10^-3 m. For a fluid of density 8.50 × 10² kg m^-3, the terminal speed is found to be 0.280 m s^-1. Calculate the viscosity of the fluid.
19M.3.HL.TZ1.10a:
State one condition that must be satisfied for the Bernoulli equation

$\frac{1}{2}$ ρv² + ρgz + ρ = constant

to apply
19M.3.HL.TZ1.10b.iii: The diameter at Y is made smaller than that at X. Explain why the pressure difference between...
18M.3.HL.TZ2.10a:
Show that the velocity of the fluid at X is about 2 ms^–1, assuming that the flow is laminar.

Hide related questions

Option B: Engineering physics » Option B: Engineering physics (Additional higher level option topics)

Option B: Engineering physics