So basically Q4 iv) OCR MEI M3 January 2010.
All parts before part iv) were fine.
Now I am going to go through my new thoughts on the situation and hopefully some bodies may confirm, reject or adjust my thinking.
So to find the time taken, I started with finding the equation which describes the motion:
Then to find the displacement when , I used the renowned formula:
Now inputting this newfound into the first formula, followed by rearrangement gave: the first time.
However, now thoughts are beginning to rearrange themselves, new patterns are being seen and new found wisdom kicks in... From looking at the mark scheme.
So if I let , and look at a normal cosine graph with period , I can find the point where I can see is going downwards.
Seeing that the particle is going downwards with , just past the point where or (depends on the way you swing), I have found that the particle travels downwards with when .
Using the substitution from earlier ( ), I can now find the time by reverting back to the original cosine function.
So, yay or nay?
M3 Simple Harmonic Motion, finding that time. Watch
- Thread Starter
- 22-05-2016 20:52
- Study Helper
- 22-05-2016 21:47
- 22-05-2016 22:01
I've just done the question and a simpler method I found was to use to find the time to travel up then add this to a quarter of the period. Let Y be the point this happens at. This gives us the time to get from A to Y (OR from Y to A) hence the time we need is the period - (time taken to go from Y to A).
I hope that made sense but it seems more straight forward to me personally in the way I work with these problems, I hope it's perhaps helped?
- Thread Starter
- 22-05-2016 22:09
Thanks, I will consider that way, as well as my own.