# Simple harmonic motion -- manipulating SHM equations

#### PeroK

Homework Helper
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2018 Award
Thanks all who reply :) Managed to solve this with @Delta2 explanation actually Answer is $\frac {2}{\sqrt 3}v$
I don't see how you can work a problem like this without labelling some specific times. After looking at the equations, the first thing I would do is:

Let $t_0, t_1$ be times when the displacement is zero and half the amplitude respectively.

Then you have $D(t_0) = 0 \ \Rightarrow \ \sin(wt_0) = 0$

Also, strictly speaking, you should be dealing with the absolute value for the speed. Alternatively, you could make a simplifying assumption that the displacements and velocities are positive, hence the sines and cosines are positive, at $t_0, t_1$.

"Simple harmonic motion -- manipulating SHM equations"

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