11판/2. 직선운동

2-20 할리데이 11판 솔루션 일반물리학

짱세디럭스 2024. 1. 11. 21:59
{v=18.0[m/s]H=90.0[m] \begin{cases} v&=18.0\ut{m/s}\\ H&=90.0\ut{m} \end{cases} (a)\ab{a} S=v0t+12at2,H=(18)t+12(g)t2 \begin{aligned} S&=v_0t+\frac{1}{2}at^2,\\ -H&=(18)t+\frac{1}{2}(-g)t^2\\ \end{aligned} t=600196133(600+2321330)[s]6.496380983846016[s]6.50[s] \begin{aligned} t&=\frac{600 }{196133}\left(600+\sqrt{2321330}\right)\ut{s}\\ &\approx 6.496380983846016 \ut{s}\\ &\approx 6.50 \ut{s}\\ \end{aligned} (b)\ab{b} 2aS=v2v02,2(g)(H)=v2(18.0)2 \begin{aligned} 2aS&=v^2-v_0^2,\\ 2(-g)(-H)&=v^2-(18.0)^2\\ \end{aligned} v=31023213310[m/s]45.70773457523354[m/s]45.7[m/s] \begin{aligned} v&=\frac{3}{10}\sqrt{\frac{232133}{10}}\ut{m/s}\\ &\approx 45.70773457523354\ut{m/s}\\ &\approx 45.7\ut{m/s}\\ \end{aligned}