Questions asked by Tom M.
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Springs: what is the height bounced by a spring, mass *m*, initial length l_0l0 compressed length l_1l1, spring constant *k*?
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1.00 g of alkali metal carbonate, M_2CO_3M2CO3, is dissolved in water and made up to 250 cm^3250cm3 in a volumetric flask. 25.00 cm^325.00cm3 portions of this solution are titrated against 0.113M hydrochloric acid. The average titre is 12.80cm^312.80cm3. What element is M?
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A pop-up toy consists of a mass m stuck to the top of a light spring of natural length l_0l0and spring constant k. The spring is compressed to length l_1l1 when the pop-up is stuck to the ground. To what height above the ground does it reach?
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A shelf of uniform density is supported by two brackets at a distance of 1/818 and 1/414 of the total length, LL, from each end respectively. Find the ratio of the reaction forces from the brackets on the shelf?
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Say I'm moving parallel to someone else and we are both accelerating in the same direction at the same rate. Would he seem stationary to me? Could we tell we were accelerating?
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Why is the boiling point of water higher than would be expected from the trend of Group 6 hydrides? Why is the boiling point of H_2TeH2Te higher than H_2SeH2Se?
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Why is the derivative of e^x=e^xex=ex? Just out of curiosity.
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In the binomial expansion of (1+ax)^n(1+ax)n, where aa and nn are constants, the coefficient of xx is 15. The coefficient of x^2x2 and of x^3x3 are equal. What is the value of aa and of nn?
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Solve 12sin^2x+7cosx-13=012sin2x+7cosx−13=0 for the range 360^o<=x<=540^o360o≤x≤540o?
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Constant acceleration: Two particles P and Q have masses 0.5kg and 0.4kg respectively. The particles are attached to the ends of a light inextensible spring. [cont]...?
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Solubility - Explain why propanone is soluble in water? Explain why magnesium chloride is soluble in cyclohexane?
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A circle C has equation x^2+y^2-6x+8y-75=0x2+y2−6x+8y−75=0, and a second circle has a centre at (15,12)(15,12) and radius 10. What are the coordinates of the point where they touch?
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What is the value of x for which ln(2x-5)-lnx=1/4ln(2x−5)−lnx=14?
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Which of the following is a redox reaction?
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What should you do if you know part of an answer, but not the whole thing? Should you leave a comment?
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When sodium chlorate (I), NaClO is heated, sodium chlorate (V) and sodium chloride are formed. What is the ionic equation for this reaction? What type of reaction is this?
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What is the reducing agent in the reaction 2HCl(aq)+H_2O_2(aq)->Cl_2(g)+2H_2O(l)?2HCl(aq)+H2O2(aq)→Cl2(g)+2H2O(l)?
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Why is the boiling point of H_2TeH2Te higher than the boiling point of H_2SH2S?
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Draw the shape of the ClF_2^+ClF+2 ion, including any lone pairs, and name the shape made by the atoms? Predict the bond angle in the ion?
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What is the systematic name of the compound CH_3CH(OH)CH_2CHOCH3CH(OH)CH2CHO?
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The graph y=ab^xy=abx passes through (2, 400)(2,400) and (5,50)(5,50). Find values for aa and bb, and, given that ab^x>kabx>k for some constant k>0k>0, show that x>log(1600/k)/log2x>log(1600k)log2 where log means log to any base?
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log_11(2x-1)=1-log_11(x+4)log11(2x−1)=1−log11(x+4) What is xx?
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Prove that sum_(r=1)^nr^5=1/12n^2(n+1)^2(2n^2+2n-1)n∑r=1r5=112n2(n+1)2(2n2+2n−1) using binomial theorem?
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Why, in terms of structure and bonding, does but-2-ene exist as two geometric isomers whereas but-1-ene does not?
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How could you find the density of an irregular object which floats in water?
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One of the most commonly used compounds in the chlorination of swimming pools is sodium hypochlorite, NaClO.NaClO. Once dissolved, an equilibrium is established between ClO^-ClO− and its conjugate acid. What is the equation of this reaction?
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Prove by induction that f(n)=2^(2n-1)+3^(2n-1)f(n)=22n−1+32n−1 is divisible by 5 for n in ZZ^+?
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Given the following information, calculate the density of sand?
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Abs(z-4+2i)=Abs(z+8-6i). In the form asqrt13, ainQQ, what is the least value of absz?
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A regular tetrahedron has vertices A, B, C and D with co-ordinates (0,0,0,), (0,1,1), (1,1,0), "and" (1,0,1) respectively. Show the angle between any two faces of the tetrahedron is arccos(1/3)?
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Challenge I came up with: what is the maximum area of the rectangle inscribed between the line y=sintheta, x=theta and x=pi-theta?
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Proof of the shortest distance from a point to a plane formula?
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Find a Cartesian Equation of the plane with contains the line (x-2)/3=(y+4)/2=(z-1)/2 and passes through the point (1,1,1)?
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Sketch the velocity-time graph for two particles colliding in vertical motion?
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Venus is an inner planet which orbits the Sun in almost the same plane as the Earth. Its average radius of orbit is 0.72 AU. Viewed from the Earth’s equator, estimate maximum number of hours before sunrise for which Venus can be observed in the night sky?
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A uniform rectangular trapdoor of mass m=4.0kg is hinged at one end. It is held open, making an angle theta=60^@ to the horizontal, with a force magnitude F at the open end acting perpendicular to the trapdoor. Find the force on the trapdoor?
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Complete the half equation?:
MnO_4^-" + X -> Mn^2+Y
What are X and Y?
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If e=(1+klamda)/(k(1-lambda)), 0<lamda<1/2 and e is the coefficient of restitution, deduce that k>1?