Comments on: Higher Physics prelim http://mrmackenzie.co.uk/2010/01/12/higher-physics-prelim/ with mr mackenzie Thu, 02 Feb 2012 22:46:16 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: mrmackenzie http://mrmackenzie.co.uk/2010/01/12/higher-physics-prelim/#comment-278 mrmackenzie Fri, 29 Jan 2010 00:29:16 +0000 http://mrmackenzie.co.uk/?p=1321#comment-278 The thing about nuclear fission is that the daughter products vary. By absorbing a neutron, U-235 becomes unstable and splits. This splitting process does not always result in the same daughter products every time, although there is some statistical information available on the *most likely* fission fragments, e.g. http://en.wikipedia.org/wiki/Fission_product_yield At Higher level, you need to be able to analyse whatever data is given in the question. Normally, this will involve a calculation of the energy released as a result of the fission processs. To calculate the energy released, you follow a similar method to momentum questions, i.e. find the total mass BEFORE fission and the total mass AFTER fission. The difference in mass (mass Before - mass AFTER) is the value of m to be used in Einstein's equation E=mcc (c squared) to determine the energy released. The thing about nuclear fission is that the daughter products vary. By absorbing a neutron, U-235 becomes unstable and splits. This splitting process does not always result in the same daughter products every time, although there is some statistical information available on the *most likely* fission fragments, e.g.

http://en.wikipedia.org/wiki/Fission_product_yield

At Higher level, you need to be able to analyse whatever data is given in the question. Normally, this will involve a calculation of the energy released as a result of the fission processs.

To calculate the energy released, you follow a similar method to momentum questions, i.e. find the total mass BEFORE fission and the total mass AFTER fission.

The difference in mass (mass Before – mass AFTER) is the value of m to be used in Einstein’s equation E=mcc (c squared) to determine the energy released.

]]> By: ahmad shatat http://mrmackenzie.co.uk/2010/01/12/higher-physics-prelim/#comment-277 ahmad shatat Thu, 28 Jan 2010 21:54:43 +0000 http://mrmackenzie.co.uk/?p=1321#comment-277 why do you think the fission of 235 into 92 and 142 not two even atoms,and who wrote about this why do you think the fission of 235 into 92 and 142 not two even atoms,and who wrote about this

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