<p>A particle executes simple harmonic motion with an amplitude of 4cm . At the mean position, velocity of the particle is&nbsp; 10cm/s. The distance of the particle from the mean position when its speed becomes 5cm/s&nbsp; is&nbsp;<span class="equation">\(\sqrt{\alpha}\)</span>cm&nbsp;, where&nbsp;<span class="equation">\(\alpha\)</span>​​​​​​​= &nbsp;________.</p>