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Physics Predictions/Thoughts (6 Viewers)

liamkk112

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this looks like a fun paper, more interesting questions than some other hsc
 

tywebb

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the cognito also agrees with the starboy/jeff>>=/beyondtutoring answer for mc
 

wizzkids

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Regarding Question 19, have a look at this. Tell me what you think. Analysing the path of the second proton gets much harder after its path has begun to curve more, but at least initially, I think the acceleration is constant in magnitude but not direction (D).
Postscript: I just finished analysing the second proton, and if it stays within the chamber, then its motion will be an ellipse. The best answer is (C).
question_19.jpg
 
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wizzkids

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Question 32. Analyse the evidence from at least three such experiments about the interaction between light and matter.
The examiners have made this question way harder than they imagined. If a scientist did not do experiments, then their work should not be mentioned. For example, Einstein did not do experiments on the interaction of light with matter. He analysed the experiments of other scientists. For example, most of Einstein's ground-breaking work on the photoelectric effect relied on the experiments of Philipp Lenard. It was Lenard who gathered all the data, which then Einstein interpreted in a new way, but Einstein didn't do the experiments. The trouble is, none of these scientists (apart from Newton) appear in the HSC syllabus.
Here is my list of top experiments involving light and matter:
(1) Isaac Newton - showed that white light could be split by a prism, and that if the colours were re-combined you could re-create white light.
(2) Francesco Grimaldi - discovered that when light passed through two narrow apertures, that the light spread out after the second aperture, a phenomenon he called "diffraction" and he correctly deduced that the light was bending around the aperture, and this indicated light was a wave.
(3) Rasmus Bartholin - discovered that light was split into two refracted rays when it passed through Iceland Spar (calcite crystals). The crystal has not one, but two refractive indices, so light has two velocities and two polarization axes when it passes through Iceland Spar. This discovery allowed scientists a convenient way to experiment with polarized light and make many new discoveries.
(4) Jean Foucault - measured the speed of light in water, showed that it was slower than the speed of light in air, and thereby disproved Newton's corpuscular theory of light.
(5) Joseph Fraunhofer - discovered dark absorption bands in the spectrum of the Sun, hypothesised that there were new elements.
(6) Gustav Kirchhoff - discovered that hot elements gave off a line spectrum, constructed the first spectroscope and then discovered dozens of new elements by spectroscopy. Also analysed the blackbody heat radiation spectrum.
(7) Philipp Lenard - showed that photoelectrons displayed a cut-off frequency for emission that depended on the identity of the metallic surface. Showed that the kinetic energy of photoelectrons was not increased by increasing the intensity of light, only by reducing the wavelength (or increasing the frequency) of the light.
 
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