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FalchionBetaMK
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Good-day. Using the Pearson EdExcel books on each module to self-teach A-level Further Maths, very difficult. Since I don't wish to consume a thread for the purpose of answering one question, feel free to submit your own problems.

Having this issue with a lot of the questions in the book where the answers seem unfeasible given my working, though I am 90% confident given the Dunning-Kruger effect that such is the result of my incompetence. Anyhow here is the question;

(Exercise 3A): 1. A particle P of mass 0.2 kg is moving on the x-axis. At time t seconds P is x metres from the origin O. The force acting on P has magnitude 2costN and acts in the direction OP. When t = 0, P is at rest at O. Calculate

a the speed of P when t = 2,
b the speed of P when t = 3,
c the time when P first comes to instantaneous rest,
d the distance OP when t = 2
e the distance OP when P first comes to instantaneous.

The answers for the following questions being;
a 9.09 ms^-1 (3 s.f.)
b 1.41 ms^-1 (3 s.f.)
c P first comes to rest when t = pi
d 14.2 m (3 s.f.)
e OP = 20 m

My problem here is that following the given examples on the prior pages I could not get anything even remotely resembling the answers, personally I did the following;
> Used f = ma (2cost = 0.2a)
> Integrated on both sides leading to (-2sint + D = 0.2v, this is where I believe I have gone wrong)
> Used t = 0, v = 0, now I get completely stuck and cannot find an answer. The examples featured both a regular number and an exponential so it was easy to follow, though I cannot grasp what I am supposed to do next.
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RDKGames
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(Original post by FalchionBetaMK)
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\displaystyle \int \cos(t) .dt = \sin(t) +c

Also put your calculator in radians mode obviously.

Then plug in t=2 and t=3 for parts a,b. For c, set v=0 and find t. For d, integrate again and find the result at t=2, then at the t= whatev your answer for c is.
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FalchionBetaMK
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(Original post by RDKGames)
\displaystyle \int \cos(t) .dt = \sin(t) +c

Also put your calculator in radians mode obviously.

Then plug in t=2 and t=3 for parts a,b. For c, set v=0 and find t. For d, integrate again and find the result at t=2, then at the t= whatev your answer for c is.
Thanks a ton for the help!
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