各位朋友帮帮忙，这里有道题急需帮助

icelant

<  align=center><FONT face="Times New Roman">朋友们只需要提供有效的解题思路就可以，直接发到我的邮箱<a href="mailticelant@163.com" target="_blank" >icelant@163.com</A> 或是直接与我的QQ15533453联系，谢谢。真诚期待大家的帮助。 </FONT></P>
<  align=center><FONT face="Times New Roman"></FONT> </P>
<  align=center>弹板跳海表演<p></p></P>
<P ><FONT size=3>由于近年来杂技表演越来越不受观众的欢迎，所以杂技团的收入也每况愈下。为了招揽观众，<FONT face="Times New Roman"> </FONT>杂技团来到某海滨城市表演时，设计了一项惊险节目——弹板跳海运动。即在离海边一定距离（一般不超过<st1:chmetcnv w:st="on" UnitName="米" SourceValue="15" HasSpace="False" Negative="False" NumberType="1" TCSC="0"><FONT face="Times New Roman">15</FONT>米</st1:chmetcnv>）的海滩上，建一高台。高台下某处置一极富弹性的斜面（用弹簧编织而成），斜面与平面成<FONT face="Times New Roman">45</FONT>度角。然后爱人能够演员从高台团身跳下，经与斜面碰撞后将起弹到海里，请你讨论以下问题：</FONT></P>
<P ><p><FONT face="Times New Roman" size=3> </FONT></p></P>
<P ><FONT size=3>问题一：请您建立演员跳的水平距离的数学模型？</FONT></P>
<P ><p><FONT face="Times New Roman" size=3> </FONT></p></P>
<P ><FONT size=3>问题二：在离海边<st1:chmetcnv w:st="on" UnitName="米" SourceValue="12" HasSpace="False" Negative="False" NumberType="1" TCSC="0"><FONT face="Times New Roman">12</FONT>米</st1:chmetcnv>的海滩上，建一<st1:chmetcnv w:st="on" UnitName="米" SourceValue="16" HasSpace="False" Negative="False" NumberType="1" TCSC="0"><FONT face="Times New Roman">16</FONT>米</st1:chmetcnv>高台，高台下<st1:chmetcnv w:st="on" UnitName="米" SourceValue="8" HasSpace="False" Negative="False" NumberType="1" TCSC="0"><FONT face="Times New Roman">8</FONT>米</st1:chmetcnv>处放一弹性斜面。问演员可否安全入海。</FONT></P>
<P ><p><FONT face="Times New Roman" size=3> </FONT></p></P>
<P ><FONT size=3>问题三：如果适当调整弹性斜面的角度，问题二的条件不边，演员若要安全入海，请你给出弹性斜面放置的角度范围。</FONT></P>
<P ><p><FONT face="Times New Roman" size=3> </FONT></p></P>
<P ><FONT size=3>问题四：请您为杂技团的该项表演写一海报，以便吸引观众前来观看。</FONT></P>
<P ><p><FONT face="Times New Roman" size=3> </FONT></p></P>

beck

< ><FONT face="Times New Roman" size=3>S=H-L+M+M*ctg(8)</FONT></P>
< ><FONT face="Times New Roman" size=3>Vt^2=2*g*S</FONT></P>
< ><FONT face="Times New Roman" size=3>Vt=sqrt(2*g*S)</FONT></P>
<P ><FONT face="Times New Roman" size=3>S1=L-M</FONT></P>
<P ><FONT face="Times New Roman" size=3>T=sqrt(2*s1/g)</FONT></P>
<P ><FONT face="Times New Roman" size=3>S2=Vt*T&gt;a    (a&lt;=15)</FONT></P>
<P ><FONT face="Times New Roman" size=3>S2=sqrt(2*g*( H-L+M+M*ctg(8)))* sqrt(2* (L-M)/g)&gt;a    (a&lt;=15)</FONT></P>
<P ><FONT size=3><FONT face="Times New Roman"> <p></p></FONT></FONT></P>
<P ><FONT face="Times New Roman" size=3>a=12  H=16  L=8
S2=sqrt(2*g*( H-L))* sqrt(2* (L)/g)&gt;a    (a&lt;=15)</FONT></P>
<P >&gt;&gt; syms g H L
&gt;&gt; g=9.8;H=16;L=8;
&gt;&gt; s=sym('sqrt(2*g*( H-L))* sqrt(2* L/g)');
&gt;&gt; simple(s)

simplify:

2*(-g*(-H+L))^(1/2)*(L/g)^(1/2)


radsimp:

2*(H-L)^(1/2)*L^(1/2)


combine(trig):

2*(g*H-g*L)^(1/2)*(L/g)^(1/2)


factor:

2*(-g*(-H+L))^(1/2)*(L/g)^(1/2)


expand:

2*(g*H-g*L)^(1/2)*(L/g)^(1/2)


combine:

2*(g*H-g*L)^(1/2)*(L/g)^(1/2)


convert(exp):

2*(g*(H-L))^(1/2)*(L/g)^(1/2)


convert(sincos):

2*(g*(H-L))^(1/2)*(L/g)^(1/2)


convert(tan):

2*(g*(H-L))^(1/2)*(L/g)^(1/2)


collect(g):

2*(g*(H-L))^(1/2)*(L/g)^(1/2)


ans =

2*(H-L)^(1/2)*L^(1/2)

&gt;&gt; subs(s)</P>
<P >ans =</P>
<P >   16.0000</P>
<P >安全</P>