(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Calculate acceleration and velocity of a piston. Stroke is 150mm and engine speed 3500rpm

Using simple harmonic motion equations

2. Relevant equations

a = -ω^2*s

v = ω*√A^2 - s^2

ω = 2*∏*f

v = velocity, a = acceleration, f = frequency

ω=angular velocity, s=displacement, A = Amplitude

3. The attempt at a solution

worked out frequency by 3500/60=58.3Hz

angular velocity = 366.31 radians/sec

Problem i have is i'm not sure what value i use for amplitude and what value i use for displacement. I believe that amplitude would be half the stroke thus being 75mm and displacement being the stroke of 150mm. However inserting these values into the equation to calculate velocity gives a negative figure which then cannot be square rooted. Any help would be appreciated. Thanks

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# SHM: Which is amplitude and which is displacement?

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