2-54 할리데이 11판 솔루션 일반물리학

$$ \begin{cases} a&=\bra{-2(t\ut{s})+8}\ut{m/s^2}\\ v(-2.0)&=11.0\ut{m/s} \end{cases} $$ $$ \begin{aligned} v&=\int a\dd t\\ &=\int (-2t+8)\dd t\\ &=-t^2+8t+C\\ \end{aligned} $$ $$ \begin{aligned} v(-2)&=-(-2)^2+8(-2)+C=11\\ C&=31\\ \end{aligned} $$ $$\therefore v(t)=-t^2+8t+31$$ $$ \begin{aligned} v(6.0)&=-(6)^2+8(6)+31\\ &=43\ut{m/s}\\ \end{aligned} $$