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I got 99.65 :)

You can convert kJ/mol into kJ/g by working out the molar mass of each alkanol (from the periodic table). For example, the molar mass of ethanol is 46g so you can divide the molar heat of combustion by 46 to work out the kJ/g

The acceleration of a rocket increases at an increasing rate. This can be shown by analysing the forces on astronauts. The two forces acting on an astronaut are upward thrust and the downward weight force. By Newton's Second Law, a = F/m so a = (T-mg)/m. Since 'm' is decreasing (as fuel is being...

re: HSC Physics Marathon Archive the back emf is reduced because the coil is rotating slower (smaller rate of change of flux thus less emf induced as per Faraday) thus the supply current is almost unopposed which can burn the motor

re: HSC Physics Marathon Archive When a spacecraft approaches a planet, its incoming speed and outgoing speed are the same relative to the planet but there is a change in direction. However relative to the sun the speed increases because the planet acquires angular momentum from planet and the...

re: HSC Physics Marathon Archive 3.2 x 10^23 kg ?

When you're deriving the equation for escape velocity you use law of conservation of energy: E(initial) = E(final) GPE + KE = GPE + KE -GmM/r + 1/2mv^2 = 0 + 0 (--> this is where I'm confused --> why is KE at infinity 0?)

why is the kinetic energy of an object an infinite distance away from earth 0?

re: HSC Chemistry Marathon Archive 2

re: HSC Physics Marathon Archive a p-type semiconductor (e.g. silicon doped with group III element) is combined with an n-type semiconductor (e.g. silicon doped with group IV element). The p-type part of the PN junction is connected to the positive terminal of a power source and the n-type half...

re: HSC Chemistry Marathon Archive monomer = ethylene, polymerised by gas phase process, 1000-3000 atm, 300C, initiation (organic peroxide --> free radicals --> attacks double bond), propagation (chain lengthens as intiator-ethylene radical continues to attack ethylene; backbiting -->...

Calculate the orbital period of Deimos, one of the two moons of Mars. Its average distance from mars is 23 400 km and its irregular shape averages about 13 km across. The mass of Mars is 6.42 x 10^23 kg, and its diameter is 6794 km. Full working please. Thanks!

How you do you know when ay is negative or positive 9.8.

can someone give me some ideas for what to write about for last year's HSC question: an inherent tension between confrontation and resolution is revealed through characterization in SHakespeare's Hamlet. To what extent does your interpretation of Hamlet align with this view. I'm a little...

re: HSC Physics Marathon Archive Ke = qV = hf - W rearrange, plug in values... W = 1.35 eV is this correct?

re: HSC Chemistry Marathon Archive also, the cycle technically isn't 'endless' because it does eventually stop when chlorine reacts with another chemical e.g. methane

is it possible to have accurate and unreliable results?

re: HSC Chemistry Marathon Archive CFCs don't contain hydrogen.

re: HSC Chemistry Marathon Archive - chloroflurocarbons = compounds containing chlorine, fluorine and carbon - thousands of tonnes released into atmosphere due to use in refrigerants, propellants etc. - cfc gradually photodissociates to produce chlorine free radical (eqn) - chlorine free...

re: HSC Physics Marathon Archive why are both of the forces down? also, can you please show me how mass dilation affects the force? thank you! - hertz tried to verify maxwell's predictions for electromagnetic waes - he set up a coil of wire with a gap in it and connected it to a high voltage...