8-22 할리데이 11판 솔루션 일반물리학 {0:Start1:hmax2:Δh=−3.0[m] \begin{cases} 0:\text{Start}\\ 1:h_{\max}\\ 2:\Delta h = -3.0\ut{m} \end{cases} ⎩⎨⎧0:Start1:hmax2:Δh=−3.0[m] {m=88[g]θ=30°v0=8.0[m/s]g=9.80665[m/s2] \begin{cases} m&=88\ut{g}\\ \theta&=30\degree\\ v_0&=8.0\ut{m/s}\\ g&=9.80665\ut{m/s^2} \end{cases} ⎩⎨⎧mθv0g=88[g]=30°=8.0[m/s]=9.80665[m/s2] v⃗0=v0cosθi^+v0sinθj^, \begin{aligned} \vec v_0 &= v_0\cos\theta\i+v_0\sin\theta\j,\\ \end{aligned} v0=v0cosθi^+v0sinθj^, put {KE:Kinetic EnergyGE:Gravitational Potential Energy \put \begin{cases} \KE : \text{Kinetic Energy}\\ \GE : \text{Gravitational Potential Energy}\\ \end{cases} put {KE:Kinetic EnergyGE:Gravitational Potential Energy (a)\ab{a}(a).. 11판/8. 퍼텐셜에너지와 에너지 보존 2024.04.01
8-21 할리데이 11판 솔루션 일반물리학 {A:M BoxB:2M BoxC:Spring \begin{cases} A:\text{M Box}\\ B:\text{2M Box}\\ C:\text{Spring}\\ \end{cases} ⎩⎨⎧A:M BoxB:2M BoxC:Spring {0:Start1:x1=0.120[m]2:x2=max(x) \begin{cases} 0:\text{Start}\\ 1:x_1=0.120\ut{m}\\ 2:x_2=\max(x)\\ \end{cases} ⎩⎨⎧0:Start1:x1=0.120[m]2:x2=max(x) {mA=M=2.80[kg]mB=2Mk=230[N/m] \begin{cases} m_A&=M=2.80\ut{kg}\\ m_B&=2M\\ k&=230\ut{N/m}\\ \end{cases} ⎩⎨⎧mAmBk=M=2.80[kg]=2M=230[N/m] $$ \put \begin{cases} \KE : \text{Kinetic Energy}\\ \GE : \text{Gravitational Potential Energy}\\ \LE : \text{Elastic Potential Energy}\\ \end{cases.. 11판/8. 퍼텐셜에너지와 에너지 보존 2024.04.01
8-20 할리데이 11판 솔루션 일반물리학 {m=265[kg]d=6.2[m]θ=39°μ=0.28g=9.80665[m/s2] \begin{cases} m&=265\ut{kg}\\ d&=6.2\ut{m}\\ \theta&=39\degree\\ \mu &= 0.28\\ g&= 9.80665\ut{m/s^2} \end{cases} ⎩⎨⎧mdθμg=265[kg]=6.2[m]=39°=0.28=9.80665[m/s2] h=dsinθh = d\sin\thetah=dsinθ ΣFy=0,\Sigma F_y=0,ΣFy=0, N0→1−mgcosθ=0N_{0\rarr1}-mg\cos\theta=0N0→1−mgcosθ=0 N0→1=mgcosθN_{0\rarr1}=mg\cos\thetaN0→1=mgcosθ ∴f0→1=μmgcosθ\therefore f_{0\rarr1}=\mu mg\cos\theta∴f0→1=μmgcosθ $$ \put \begin{cases} \KE : \text{Kinetic Energy}\\ \GE : \text{Gravitational Potential Energy}\\ \TE : \text{Thermal Energy}\\ \end{case.. 11판/8. 퍼텐셜에너지와 에너지 보존 2024.04.01
8-19 할리데이 11판 솔루션 일반물리학 {m=1750[kg]θ=5.0°S=65[m]vi=32[km/h]=809[m/s]vf=40[km/h]=1009[m/s]g=9.80665[m/s2] \begin{cases} m&=1750\ut{kg}\\ \theta&=5.0\degree\\ S&=65\ut{m}\\ v_i&=32\ut{km/h}=\frac{80}{9}\ut{m/s}\\ v_f&=40\ut{km/h}=\frac{100}{9}\ut{m/s}\\ g&=9.80665\ut{m/s^2} \end{cases} ⎩⎨⎧mθSvivfg=1750[kg]=5.0°=65[m]=32[km/h]=980[m/s]=40[km/h]=9100[m/s]=9.80665[m/s2] put {KE:Kinetic EnergyGE:Gravitational Potential EnergyME:Mechanical Energy \put \begin{cases} \KE : \text{Kinetic Energy}\\ \GE : \text{Gravitational Potential Energy}\\ \ME : \text{Mechanical Energy} \end{cases} put ⎩⎨⎧KE:Kinetic EnergyGE:Gravitational Potential EnergyME:Mechanical Energy $$ \begin{aligned} \Delta y &= -S\sin\theta\\ &=-65\sin5\degree\\ \e.. 11판/8. 퍼텐셜에너지와 에너지 보존 2024.04.01
8-18 할리데이 11판 솔루션 일반물리학 {F⃗0→2.00[m]=+3.00i^[N]F⃗2.00→3.00[m]=+5.00i^[N]F⃗3.00→8.00[m]=0F⃗8.00→11.0[m]=−4.00i^[N]F⃗11.0→12.0[m]=−1.00i^[N]F⃗12.0→15.0[m]=0 \begin{cases} \vec F_{0\rarr2.00\ut{m}}&=+3.00\i\ut{N}\\ \vec F_{2.00\rarr3.00\ut{m}}&=+5.00\i\ut{N}\\ \vec F_{3.00\rarr8.00\ut{m}}&=0\\ \vec F_{8.00\rarr11.0\ut{m}}&=-4.00\i\ut{N}\\ \vec F_{11.0\rarr12.0\ut{m}}&=-1.00\i\ut{N}\\ \vec F_{12.0\rarr15.0\ut{m}}&=0\\ \end{cases} ⎩⎨⎧F0→2.00[m]F2.00→3.00[m]F3.00→8.00[m]F8.00→11.0[m]F11.0→12.0[m]F12.0→15.0[m]=+3.00i^[N]=+5.00i^[N]=0=−4.00i^[N]=−1.00i^[N]=0 $$ \begin{cases} \int_0^2F\dd x&=3x\\ \int_2^3F\dd x&=5(x-2)\\ \int_3^8F\dd x&=0\\ \int_8^{11}F\dd x&=-4(x-8)\\ \int_.. 11판/8. 퍼텐셜에너지와 에너지 보존 2024.03.29
8-17 할리데이 11판 솔루션 일반물리학 {mA=2.00[kg]mB=4.00[kg]θ=30.0°v0=0ΔyB=−32.0[cm]=−0.32[m] \begin{cases} m_A&=2.00\ut{kg}\\ m_B&=4.00\ut{kg}\\ \theta&=30.0\degree\\ v_0&=0\\ \Delta y_B&=-32.0\ut{cm}=-0.32\ut{m} \end{cases} ⎩⎨⎧mAmBθv0ΔyB=2.00[kg]=4.00[kg]=30.0°=0=−32.0[cm]=−0.32[m] sinθ=ΔyAΔdA=ΔyA−ΔyB∴ΔyA=−ΔyBsinθ \begin{aligned} \sin\theta &= \frac{\Delta y_A}{\Delta d_A}\\ &= \frac{\Delta y_A}{-\Delta y_B}\\ \therefore \Delta y_A&=-\Delta y_B\sin\theta \end{aligned} sinθ∴ΔyA=ΔdAΔyA=−ΔyBΔyA=−ΔyBsinθ $$ \put \begin{cases} \KE : \text{Kinetic Energy}\\ \GE : \text{Gravitational Potential Energy}\\.. 11판/8. 퍼텐셜에너지와 에너지 보존 2024.03.29
8-16 할리데이 11판 솔루션 일반물리학 {m=0.30[kg]v=4.00[m/s]hmax=0.80[m]g=9.80665[m/s2] \begin{cases} m&=0.30\ut{kg}\\ v&=4.00\ut{m/s}\\ h_{\max}&=0.80\ut{m}\\ g&=9.80665\ut{m/s^2} \end{cases} ⎩⎨⎧mvhmaxg=0.30[kg]=4.00[m/s]=0.80[m]=9.80665[m/s2] put {KE:Kinetic EnergyGE:Gravitational Potential Energy \put \begin{cases} \KE : \text{Kinetic Energy}\\ \GE : \text{Gravitational Potential Energy}\\ \end{cases} put {KE:Kinetic EnergyGE:Gravitational Potential Energy $$ \begin{aligned} \Delta E &=E_2-E_1\\ &=\GE_2-\KE_1\\ &=mgh_2-\frac{1}{2}m{v_1}^2\\ &=\frac{6 g}{25}-\frac{12}{5}\\ &=-0.046404\ut{J}\\ &=-4.6404\times10^{-2}\ut{J}\\ &\app.. 11판/8. 퍼텐셜에너지와 에너지 보존 2024.03.29
8-15 할리데이 11판 솔루션 일반물리학 {m=425[g]L=2.4[m]θi=30.0°vi=0g=9.80665[m/s2] \begin{cases} m&=425\ut{g}\\ L&=2.4\ut{m}\\ \theta_i&=30.0\degree\\ v_i&=0\\ g&=9.80665\ut{m/s^2}\\ \end{cases} ⎩⎨⎧mLθivig=425[g]=2.4[m]=30.0°=0=9.80665[m/s2] put {KE:Kinetic EnergyGE:Gravitational Potential Energy \put \begin{cases} \KE : \text{Kinetic Energy}\\ \GE : \text{Gravitational Potential Energy}\\ \end{cases} put {KE:Kinetic EnergyGE:Gravitational Potential Energy ΣEi=ΣEf,\Sigma E_i=\Sigma E_f,ΣEi=ΣEf, KEi+GEi=KEf+GEfmgyi=12mvf2+mgyf2gyi=vf2+2gyf \begin{aligned} \KE_i+\GE_i&=\KE_f+\GE_f\\ mgy_i&=\frac{1}{2}m{v_f}^2+mgy_f\\ 2gy_i&={v_f}^2+2gy_f\\ \end{aligned} KEi+GEimgyi2gyi=KEf+GEf=21mvf2+mgyf=vf2+2gyf $$y=L-L\cos\theta=L.. 11판/8. 퍼텐셜에너지와 에너지 보존 2024.03.29
8-14 할리데이 11판 솔루션 일반물리학 (풀이자 주 : 일반적인 디젤기관차의 출력은 3000마력, 2MW 수준입니다. 그리고 2mW는 엄청나게 작은 출력으로, 선풍기를 꺼뒀을때의 대기전력 조차 200mW 수준입니다. 현실적으로 오타로 간주하고 기관차의 출력을 2MW로 두고 풀겠습니다. 만일 기관차의 출력을 2mW로 두고 푼다면 답은 달라집니다.) {P=2.0[MW]=2.0×103[W]t=6.0[min]=360[s]vi=10[m/s]vf=25[m/s] \begin{cases} P&=2.0\ut{MW}=2.0\times10^{3}\ut{W}\\ t&=6.0\ut{min}=360\ut{s}\\ v_i&=10\ut{m/s}\\ v_f&=25\ut{m/s}\\ \end{cases} ⎩⎨⎧Ptvivf=2.0[MW]=2.0×103[W]=6.0[min]=360[s]=10[m/s]=25[m/s] (a)\ab{a}(a) $$ \begin{aligned} P&=\frac{W}{t}\\ &=\frac{\Delta \KE}{t}\\ &=\frac{\KE_f-\KE_i}.. 11판/8. 퍼텐셜에너지와 에너지 보존 2024.03.29
8-13 할리데이 11판 솔루션 일반물리학 {m=1700[kg]t=30[s]v=82[km/h]=2059[m/s] \begin{cases} m&=1700\ut{kg}\\ t&=30\ut{s}\\ v&=82\ut{km/h}=\frac{205}{9}\ut{m/s} \end{cases} ⎩⎨⎧mtv=1700[kg]=30[s]=82[km/h]=9205[m/s] (a)\ab{a}(a) KE=12mv2,\KE=\frac{1}{2}mv^2,KE=21mv2, KE=12⋅1700⋅(2059)2=3572125081[J]≈441003.0864197531[J]≈4.4×105[J]≈0.44[MJ] \begin{aligned} \KE&=\frac{1}{2}\cdot 1700 \cdot \(\frac{205}{9}\)^2\\ &=\frac{35721250}{81}\ut{J}\\ &\approx 441003.0864197531\ut{J}\\ &\approx 4.4 \times 10^5 \ut{J}\\ &\approx 0.44 \ut{MJ}\\ \end{aligned} KE=21⋅1700⋅(9205)2=8135721250[J]≈441003.0864197531[J]≈4.4×105[J]≈0.44[MJ] (b)\ab{b}(b) $$ \begin{aligned} P&=\frac{W}{t}\\ &.. 11판/8. 퍼텐셜에너지와 에너지 보존 2024.03.29