<span>дано:</span>
<span>S=25</span>
<em><span>μ</span></em><span>=</span><span>0,05</span>
<span>V=0</span>
<span>Vo-?</span>
<span><span> </span></span>По второму закону Ньютона F=ma, <span><span> </span>на санки действует сила трения, под. действием которой санки останавливаются<span> </span></span>Fтр= ma, с другой стороны Fтр=<em /><em><span>μ</span></em><span>N</span><span>, </span><span>N</span><span>=</span><span>mg</span>
<span>F</span>тр<span>=</span><em><span> μ</span></em><span>mg,<span> </span><span> </span></span><em><span>μ</span></em><span>mg=</span><span> ma,</span><em><span><span> </span><span> </span>μ</span></em><span>g=</span><span> a, S=Vo^2/2a, a=Vo^2/2S</span>
<em><span><span> </span><span> </span>μ</span></em><span>g=</span><span> Vo^2/2S, <span> </span>Vo^2=2S</span><em><span> μ</span></em><span>g</span>
<span>Vo^2=2*25*0,05*10=25</span><span>м</span><span>2</span><span>/с</span><span>2</span>
<span>Vo=</span><span>5</span><span>м</span><span>/c</span>