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Full Version: Back to basics- Laws of Motion needed for headway calcs
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After we had an initial discussion at our study group, it was clear that memory fades with the passage of time. Although all of those present had done the sort of calculations before that are needed for braking calculations and stopping headway etc, doing the sums was not as free flowing as it should have been. Remember, although it is an exam to signal the layout and there are marks for showing the right calculations, you should not have to waste time thinking about the formulae that you are going to use.

The information on the attached sheet comes from notes I had from when I was doing A levels (who says you never put things from school into practice). Clearly, you only need to remember the formulae and not the derivation, but if you understand the derivation, you will be in a better position to understand what the formulae are calculating. On the other hand, if you remember the method and your mind does go blank in the exam, you might be able to redeem things by developing the required expression from first principles.

You may of course know simplified versions of these for a particular set of circumstances. Beware
24 views and no submissions? I put myself out of the running by broaching the subject with a long-established engineer at work and having a slightly mortifying lesson on equations and being shown step by step how to arrive at the answers.

I have forgotten a lot but anyone in the same boat, take heart that a little familiarity with the problems and it seems to bounce back.

BTW 0.981 seconds is NOT the answer to the first problem and doing the second one by drawing it graphically is probably missing the point. Hoping my mistakes will help others to feel better about their ability.
Hmmm, on the basis that there are not any offers for correct solutions to the examples, can I assume that either a) you are all far more clever that we gave credit for; b) you are all far less clever than we feared; or c) the offer of smug points alone is not enough incentive to get you to go pulic with your ideas. Perhaps if I up the stakes to a mars bar?

If you are stuggling with this sort of calculation, please let us know so we can offer some more information to help with specific areas.

Peter