help! Ap physics B Problem!!

[ra2000a]

<p>hey .. can someone help me with this AP Physics problem?</p>

<p><a href="http://docushare.capousd.org/docushare/dsweb/GetRendition/Document-158/html%5B/url%5D"&gt;http://docushare.capousd.org/docushare/dsweb/GetRendition/Document-158/html&lt;/a&gt;&lt;/p>

<p>its on work and energy, but i cant seem to do it!! thanks</p>