11판/9. 질량중심과 선운동량

9-55 할리데이 11판 솔루션 일반물리학

짱세디럭스 2024. 4. 30. 18:40
{vi=7600[m/s]mA=290.0[kg]mB=150.0[kg]M=mA+mB=440[kg]vAB=910.0[m/s] \begin{cases} v_i&=7600\ut{m/s}\\ m_A&=290.0\ut{kg}\\ m_B&=150.0\ut{kg}\\ M&=m_A+m_B=440\ut{kg}\\ v_{A\larr B}&=910.0\ut{m/s} \end{cases} {vAB=vAvBΔΣp=0 \begin{cases} v_{A\larr B}&=v_A-v_B\\ \Delta \Sigma \vec p&=0 \end{cases} {vAB=vAvBMvi=mAvA+mBvB \begin{cases} v_{A\larr B}&=v_A-v_B\\ Mv_i&=m_Av_A+m_Bv_B \end{cases} {vA=vi+mBMvABvB=vimAMvAB \begin{cases} v_A&=v_i+\cfrac{m_B}{M}v_{A\larr B}\\ v_B&=v_i-\cfrac{m_A}{M}v_{A\larr B}\\ \end{cases} (a)\ab{a} vA=vi+mBMvAB=17402522[m/s]7910.227272727273[m/s]7910[m/s] \begin{aligned} v_A&=v_i+\cfrac{m_B}{M}v_{A\larr B}\\ &=\frac{174025}{22}\ut{m/s}\\ &\approx 7910.227272727273\ut{m/s}\\ &\approx 7910\ut{m/s}\\ \end{aligned} (b)\ab{b} vA=vimAMvAB=15400522[m/s]7000.227272727273[m/s]7000[m/s] \begin{aligned} v_A&=v_i-\cfrac{m_A}{M}v_{A\larr B}\\ &=\frac{154005}{22}\ut{m/s}\\ &\approx 7000.227272727273\ut{m/s}\\ &\approx 7000\ut{m/s}\\ \end{aligned} (c)\ab{c} KEAi=12mAvi2=8.3752×109[J]8.375×109[J]8375[MJ] \begin{aligned} \KE_{Ai}&=\frac{1}{2}m_A{v_i}^2\\ &=8.3752\times10^9\ut{J}\\ &\approx 8.375\times10^9\ut{J}\\ &\approx 8375\ut{MJ}\\ \end{aligned} KEBi=12mBvi2=4.332×109[J]=4332[MJ] \begin{aligned} \KE_{Bi}&=\frac{1}{2}m_B{v_i}^2\\ &=4.332\times10^9\ut{J}\\ &= 4332\ut{MJ}\\ \end{aligned} KEi=12Mvi2=1.27072×1010[J]1.271×1010[J]12.71[GJ] \begin{aligned} \KE_{i}&=\frac{1}{2}M{v_i}^2\\ &=1.27072\times10^{10}\ut{J}\\ &\approx 1.271\times10^{10}\ut{J}\\ &\approx 12.71\ut{GJ}\\ \end{aligned} (d)\ab{d} KEAf=12mAvA2=4391281590625484[J]9.07289584839876×109[J]9.073×109[J]9073[MJ] \begin{aligned} \KE_{Af}&=\frac{1}{2}m_A{v_A}^2\\ &=\frac{4391281590625}{484}\ut{J}\\ &\approx 9.07289584839876\times10^9\ut{J}\\ &\approx 9.073\times10^9\ut{J}\\ &\approx 9073\ut{MJ}\\ \end{aligned} KEBf=12mBvB2=3439043303625484[J]7.105461371126033×109[J]7.105×109[J]7105[MJ] \begin{aligned} \KE_{Bf}&=\frac{1}{2}m_B{v_B}^2\\ &=\frac{3439043303625}{484}\ut{J}\\ &\approx 7.105461371126033\times10^9\ut{J}\\ &\approx 7.105\times10^9\ut{J}\\ &\approx 7105\ut{MJ}\\ \end{aligned} KEf=12mAvA2+12mBvB2=3915162447125242[J]1.6178357219524794×1010[J]1.618×1010[J]16.18[GJ] \begin{aligned} \KE_{f}&=\frac{1}{2}m_A{v_A}^2+\frac{1}{2}m_B{v_B}^2\\ &=\frac{3915162447125}{242}\ut{J}\\ &\approx 1.6178357219524794\times10^{10}\ut{J}\\ &\approx 1.618\times10^{10}\ut{J}\\ &\approx 16.18\ut{GJ}\\ \end{aligned} (e)\ab{e} by Spring Energy\text{by Spring Energy}