Thursday, March 25, 2010

Block Test update

I am pleased to know some students are getting the crux of it. I discovered my mistake through Goutham who gave an excellent working that made me realise my mistake. I just posted in previous post that the potential distance graph should have a value of 35 V on the yaxis. It should be 160 V as shown in Goutham's calc. For the graph , I cannot take the answer from part c) the increase in EPE because the distance traveled until it comes to a rest is much larger so is the inrease in EPE. Increase in EPE is in fact the initial KE as final KE is zero. Hence answer is 160 V. Good work Goutham though you did not score full mark. At least you shot down a few whom I thought scored full mark. Many students wrote the symbol qV but mistook it for velocity and hence mess up. Some students know the change in KE formula but instead of squaring the velocity first and deduct they deduct the velocity and then square. Some problem with your maths!