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# SHM watch

1. http://www.ocr.org.uk/Images/60451-q...nian-world.pdf
the velocity of the mass is proportional to displacement- why is this false if v=2pi*f*A?
2. a is proportional to displacement by definition of SHM

so a = kx (k is actually -omega2)

rewritten as v/t = -omega2 * x

rewritten as v = -omega2 * x * t

For v to be proportional to x, -omega2 * t would have to be a constant. Clearly this is not the case because t varies.

It cannot be proportional to displacement.

Btw that equation in your original post can only be applied where the amplitude = x, - before then you must use v = -A * 2pi * f * sin (2pi * f * t)
3. (Original post by Student403)
a is proportional to displacement by definition of SHM

so a = kx (k is actually -omega2)

rewritten as v/t = -omega2 * x

rewritten as v = -omega2 * x * t

For v to be proportional to x, -omega2 * t would have to be a constant. Clearly this is not the case because t varies.

It cannot be proportional to displacement.

Btw that equation in your original post can only be applied where the amplitude = x, - before then you must use v = -A * 2pi * f * sin (2pi * f * t)
thanks
4. (Original post by runny4)
thanks
No problem

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