{"id":341,"date":"2017-08-05T10:12:17","date_gmt":"2017-08-05T10:12:17","guid":{"rendered":"http:\/\/tmfwarszawa.pl\/?page_id=341"},"modified":"2019-02-09T22:59:57","modified_gmt":"2019-02-09T22:59:57","slug":"zadania-2016-ang","status":"publish","type":"page","link":"https:\/\/tmfwarszawa.pl\/index.php\/archiwum\/sklad-druzyny-2016\/zadania-2016-ang\/","title":{"rendered":"Zadania 2016 (ang)"},"content":{"rendered":"
\u201eIt is much easier to recognize error than to find truth.\u201d<\/em>
\nGoethe<\/div>\n
<\/div>\n
1. Invent yourself<\/strong><\/div>\n
Truly random numbers are a very valuable and rare resource.\u00a0Design, produce, and test a mechanical device for producing\u00a0random numbers. Analyse to what extent the randomness\u00a0produced is safe against tampering.<\/div>\n
<\/div>\n
2. Lagging Pendulum<\/strong><\/div>\n
A pendulum consists of a strong thread and a bob. When the\u00a0pivot of the pendulum starts moving along a horizontal\u00a0circumference, the bob starts tracing a circle which can have\u00a0a smaller radius, under certain conditions. Investigate the\u00a0motion and stable trajectories of the bob.<\/div>\n
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3. Acoustic Lens<\/strong><\/div>\n
Fresnel lenses with concentric rings are widely used in optical\u00a0applications, however a similar principle can be used to focus\u00a0acoustic waves. Design and produce an acoustic lens and\u00a0investigate its properties, such as amplification, as a function\u00a0of relevant parameters.<\/div>\n
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\n
4. Super Ball<\/strong><\/div>\n
Throw a highly elastic ball into the space between two plates.\u00a0The ball starts bouncing and under some circumstances can\u00a0even be projected back to you. Investigate the motion of the\u00a0ball and parameters influencing the motion, including the\u00a0orientation of the plates.<\/div>\n
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5.\u00a0Ultrahydrophobic Water<\/strong><\/div>\n
Set a dish filled with soapy water onto a loudspeaker or other\u00a0vibrator. When it oscillates, it is possible to hold small droplets\u00a0on its surface for a long time. Explain and investigate the\u00a0phenomenon.<\/div>\n
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6. Electric Honeycomb<\/strong><\/div>\n
Set a vertically oriented steel needle over a horizontal metallic\u00a0plate. Place some oil onto the plate. If you apply constant high\u00a0voltage between the needle and the plate, a cell structure\u00a0appears on the surface of the liquid. Explain and investigate\u00a0this phenomenon.<\/div>\n
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7.\u00a0Hot Water Fountain<\/strong><\/div>\n
Partially fill a Mohr pipette with hot water. Cover the top of the\u00a0pipette with your thumb. Turn the tip upwards and observe the\u00a0fountain exiting the tip. Investigate the parameters describing\u00a0the height of the fountain, and optimize them to get the\u00a0maximum height.<\/div>\n
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\n
8. Magnetic Train<\/strong><\/div>\n
Button magnets are attached to both ends of a small\u00a0cylindrical battery. When placed in a copper coil such that the\u00a0magnets contact the coil, this \u201etrain\u201d starts to move. Explain\u00a0the phenomenon and investigate how relevant parameters\u00a0affect the train\u2019s speed and power.<\/div>\n
<\/div>\n
\n
9.\u00a0Water Waves<\/strong><\/div>\n
Generate a water wave with a vertically oscillating horizontal\u00a0cylinder. When varying the excitation frequency and\/or\u00a0amplitude, the water seems to drift away from or towards the\u00a0cylinder. Investigate the phenomenon.<\/div>\n
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10.\u00a0Light Rings<\/strong><\/div>\n
Let a liquid jet fall onto a\u00a0surface. If the contact point is\u00a0illuminated by a laser beam,\u00a0rings of light around the jet can\u00a0be observed (see Figure).\u00a0Investigate the light rings and\u00a0determine how they depend on\u00a0relevant parameters of the\u00a0whole system.<\/div>\n
<\/div>\n
\n
11.\u00a0Rolling on a Disc<\/strong><\/div>\n
If you put a light rolling object\u00a0(e.g. a ring, a disc, or a sphere)\u00a0on a horizontal rotating disc, it\u00a0may start moving without being\u00a0expelled from the disc. Explain\u00a0how different types of motion\u00a0depend on the relevant parameters.<\/div>\n
<\/div>\n
\n
12.\u00a0Van der Pauw Method<\/strong><\/div>\n
It is known that conductivity of a material can be measured\u00a0independently of the sample shape, as long as the sample has\u00a0one border (no holes). To what extent can such a method be\u00a0applied? Investigate and explain such measurements if the\u00a0sample has holes.<\/div>\n
<\/div>\n
\n
13. Paper Vice<\/strong><\/div>\n
Take two similar paperback books and interleave a few pages\u00a0at a time. Push the books together. Hold the two books by their\u00a0spines and try to pull them apart. Investigate the parameters\u00a0that set the limits of being able to separate the books.<\/div>\n
<\/div>\n
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14.\u00a0Sensitive Flame<\/strong><\/div>\n
A combustible gas (e.g. propane) streams vertically out of a\u00a0fine nozzle and then through a fine metallic mesh at a distance\u00a0of about 5 cm. The gas is lit and produces a flame above the\u00a0mesh. Under some circumstances, this flame reacts very\u00a0sensitively to sound. Investigate the phenomenon and the\u00a0relevant parameters.<\/div>\n
<\/div>\n
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15.\u00a0Contactless Calliper
\n<\/strong><\/div>\n
Invent and construct an optical device that uses a laser pointer\u00a0and allows contactless determination of thickness, refractive\u00a0index, and other properties of a glass sheet.<\/div>\n
<\/div>\n
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16.\u00a0Frisbee Vortices<\/strong><\/div>\n
When a vertical plate is partially submerged in water and\u00a0pulled in a direction normal to the plate, a pair of vortices is\u00a0created in the surface of the water. Under certain conditions,\u00a0these vortices travel along the surface for a long distance.\u00a0Investigate the parameters influencing the motion and stability\u00a0of these vortices.<\/div>\n
<\/div>\n
\n
17.\u00a0Crazy Suitcase<\/strong><\/div>\n
When one pulls along a two wheeled suitcase, it can under\u00a0certain circumstances wobble so strongly from side to side\u00a0that it can turn over. Investigate this phenomenon. Can one\u00a0suppress or intensify the effect by varied packing of the\u00a0luggage?<\/div>\n<\/div>\n
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\u201eIt is much easier to recognize error than to find truth.\u201d Goethe 1. Invent yourself Truly random numbers are a very valuable and rare resource.\u00a0Design, produce, and test a mechanical device for producing\u00a0random numbers. Analyse to what extent the randomness\u00a0produced is safe against tampering. 2. Lagging Pendulum A pendulum consists of a strong thread and […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":335,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"jetpack_post_was_ever_published":false,"footnotes":""},"class_list":["post-341","page","type-page","status-publish","hentry"],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/P4R8YU-5v","jetpack-related-posts":[],"jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/tmfwarszawa.pl\/index.php\/wp-json\/wp\/v2\/pages\/341","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tmfwarszawa.pl\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/tmfwarszawa.pl\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/tmfwarszawa.pl\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tmfwarszawa.pl\/index.php\/wp-json\/wp\/v2\/comments?post=341"}],"version-history":[{"count":3,"href":"https:\/\/tmfwarszawa.pl\/index.php\/wp-json\/wp\/v2\/pages\/341\/revisions"}],"predecessor-version":[{"id":1587,"href":"https:\/\/tmfwarszawa.pl\/index.php\/wp-json\/wp\/v2\/pages\/341\/revisions\/1587"}],"up":[{"embeddable":true,"href":"https:\/\/tmfwarszawa.pl\/index.php\/wp-json\/wp\/v2\/pages\/335"}],"wp:attachment":[{"href":"https:\/\/tmfwarszawa.pl\/index.php\/wp-json\/wp\/v2\/media?parent=341"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}