I really need helpo with this question. I am having to revise over easter for the three week break and i need a solution to this. I have all the past exam papers but the lecturere doesnt have any past paper solutions and his lecture notes are vague. TO top it off i wondered if there were any good books with worked examples and questions?(adsbygoogle = window.adsbygoogle || []).push({});

Here is my problem.

At time t, the position vector of a point P, on a fairground ride is given by:

r(t) = (2cost + cos4t)i + (2sint + sin4t)j m

Find its acceleration, F, at time t. Show that:

|f|^2 = 260 + 64 cos3t m^2s^-4

Ok thats the problem.

Now i have managed to get the velocity by differentiation and then the acceleration which works out to be:

a(t) = (-2cost-16cos4t)i + (-2sint-16sin4t)j

But i cant then get this expression to work out to |f|^2 = 260 + 64 cos3t...

Can anyone help?

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# Position vectors

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