#160;        <span class="comment">! Compute the bristle velocity</span></div>
<div class="line"><a name="l00444"></a><span class="lineno">  444</span>&#160;        dzdt = velocity - kz * abs(velocity) * z / g</div>
<div class="line"><a name="l00445"></a><span class="lineno">  445</span>&#160;    <span class="keyword">end function</span></div>
<div class="line"><a name="l00446"></a><span class="lineno">  446</span>&#160; </div>
<div class="line"><a name="l00447"></a><span class="lineno">  447</span>&#160;<s