Whenever you're confused about how to calculate some quantity, try going back to the definition.

Think carefully about what the definition of average acceleration is:

$$\vec a_\textrm{avg}\equiv\frac{\vec v_\textrm{final}-\vec v_\textrm{initial}}{\Delta t_\textrm{elapsed}}.$$

Which velocities does this equation depend on? Which velocities does it not depend on?

Average acceleration when more than two different velocities occur
I am using a span inside anchor tag which are inside &lt;li&gt;. Due to some unknown reason, one anchor tag is clickable and other is partially clickable (only the &lt;span&gt; part). Below is the code:

&lt;div id="catIcons"&gt;
  &lt;ul class="catList"&gt;
    &lt;li&gt;&lt;a href="" title="" class="catAir"&gt;&lt;span&gt;Travel &amp;amp; Airline&lt;/span&gt;&lt;/a&gt;&lt;/li&gt;
    &lt;li&gt;&lt;a href="" title="" class="catEcom"&gt;&lt;span&gt;eCommerce &amp;amp; Coupons&lt;/span&gt;&lt;/a&gt;&lt;/li&gt;
  &lt;/ul&gt;
  &lt;ul class="catList"&gt;
    &lt;li&gt;&lt;a href="" title="" class="catSearch"&gt;&lt;span&gt;Classifieds &lt;/span&gt;&lt;/a&gt;&lt;/li&gt;
    &lt;li&gt;&lt;a href="" title="" class="catSocial"&gt;&lt;span&gt;Social Media &amp;amp; UCG&lt;/span&gt;&lt;/a&gt;&lt;/li&gt;
  &lt;/ul&gt;
  &lt;div class="clear"&gt;&lt;/div&gt;
&lt;/div&gt;


CSS Used:

.catList{width:142px; float:left; margin:0 7px 0 0;list-style:none;padding:0;}
.catList li{margin-bottom:5px;}
.catList li a{display:block;padding-top:60px;}
.catList li span{font-size:11px;font-weight:normal; color:#fff; text-align:center; padding:2px 0; margin:0 auto; display:block; background-color:#2A79B2; -moz-border-radius:5px; -webkit-border-radius:5px; border-radius:5px;}
.catAir{background:url('/images/category_icons.jpg') no-repeat 44px 8px;}
.catEcom{background:url('/images/category_icons.jpg') no-repeat -492px 8px;}


Please refer to this link for more information: http://184.106.132.165/index.php

Thank you
