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When I enter sin(2$\pi$ x 260 x 0.50) into my calculator I get the answer 0.9929363607.

However the solutions say that the answer should be 0.894.

What have I done wrong ?

The question is "A plucked guitar string vibrates at 260Hz with an amplitude of 2.0mm. The vibration is timed from when the string moves through the centre of its oscillation. Assuming the motion is SHM(simple harmonic motion), find the displacement of the string after 0.50s."

I have used the equation for displacement:

X = ASin2$\pi$ft

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    you must choose the option radians on your calculator – 2017-01-12
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    @Dr.SonnhardGraubner: that would yield $0$. – 2017-01-12
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    i got this here $$0.00000006665375800$$ – 2017-01-12
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    @Dr.SonnhardGraubner: in the old days, $\sin(260\pi)$ was $0$. :) – 2017-01-12
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    is this in degrees? – 2017-01-12
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    I put the calculator in rad mode but like @YvesDaoust said it have me 0? – 2017-01-12
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    @Dr.SonnhardGraubner: you recommended to switch to radians. Anyway, $\sin(260\pi°)=0.99293636068416457\cdots$. – 2017-01-12
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    There is something wrong with your question. The presence of $\pi$ usually indicates that the argument is in radians. But that doesn't fit with the given solution. Nor does it in degrees. IMO, what you have done wrong: copy the question. – 2017-01-12
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    Post your whole answer and the question so that we know if 260, 0.50 and 2π are in radian or degree. – 2017-01-12
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    It does say to put the calculator in radian mode but when I have done this I get 0 – 2017-01-12

1 Answers 1

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$$2\sin(2\pi\cdot260\cdot0.5)=0.$$

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    So is there a mistake in the answer then ? Because that is giving a different answer. – 2017-01-12
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    @Dan: unless $0.894=0$ :-) – 2017-01-12