솔루션피아

(a) $$ \begin{aligned} \\ v_{e1} &= \frac{v_1 + v_2}{2}= \frac{\frac{d}{t_1}+\frac{d}{t_2}}{2} \\ &= \frac{d}{2} \left( \frac{1}{t_1}+\frac{1}{t_2}\right) \\ &= \frac{d}{2} \frac{t_1+t_2}{t_1t_2} \\ &= \frac{d(t_1+t_2)}{2t_1t_2}\ne v_e \end{aligned} $$ $$ \begin{aligned} \\ v_{e2} &= \frac{d}{\bar t}= \frac{d}{\frac{t_1+t_2}{2}} \\ &= \frac{2d}{t_1+t_2} \cdots({2-10-1} ) \\ &= \frac{d_1+d_2}{t_1..

($L_1=1\ut{km}$ 로 추정함.) $$ \begin{cases} S &= 1\ut{km} \\ t_1 &= 2\ut{min}+27.95\ut{s} = 147.95\ut{s} \\ t_2 &= 2\ut{min}+28.15\ut{s} = 148.15\ut{s} \\ L_2 &= L_1 + \Delta L \\ v_1 &> v_2 \end{cases} $$ $$ \begin{aligned} v_1 &> v_2 \\ \frac{L_1}{t_1} &> \frac{L_2}{t_2} \\ \frac{L_1}{t_1} &> \frac{L_1 + \Delta L}{t_2} \\ \frac{L_1}{t_1} &> \frac{L_1}{t_2}+\frac{\Delta L}{t_2} \\ \\ \frac{\Delta ..

$$ \begin{cases} v_w &= 3.50\ut{m/s} \\ d &= 0.25\ut{m} \\ L &= 1.75\ut{m} \end{cases} $$ (a) $$ \put \begin{cases} n &= \text{Human On Wall Number}\ut{EA} \\ t_k &= \text{Human k to Wall Time}\ut{s} \\ t &= \text{Overall Time}\ut{s} \end{cases} $$ $$ \begin{cases} t_1 &= \frac{L}{v_w} \\ t_2 &= t_1 + \frac{L}{v_w} \\ t_3 &= t_2 + \frac{L}{v_w} \\ \vdots \\ \Delta t &= \frac{L}{v_w} \end{cases} ..

$$ \begin{aligned} & \begin{cases} S_0 &= 40\ut{km} \\ \abs{v_{\text{BIRD}}} &= 36\ut{km/h} \\ v_A &= 16\ut{km/h} \\ v_B &= -25\ut{km/h} \end{cases}\\ \end{aligned} $$ (a) $$ \begin{aligned} \\ \Ans &= \Sigma\abs{S_{\text{BIRD}}} = ? \\ &= \Sigma\abs{v_{\text{BIRD}} \cdot t_{\text{BIRD}}} \\ &=\abs{v_{\text{BIRD}}}\cdot \Sigma\abs{t_{\text{BIRD}}} \\ &=\abs{v_{\text{BIRD}}}\cdot t_{\text{CARCRAS..

$$ \begin{cases} S &= 200\ut{m} \\ t &= 6.509\ut{s} \\ \Delta v &= 19\ut{km/h} \end{cases} $$ $$ \begin{aligned} & \\ \Ans &= t = ? \\&= \frac{S}{v} = \frac{S}{v_0+\Delta v} \\&= \frac{S}{\frac{S}{t}+\Delta v} \\&= \frac{200\ut{m}}{\frac{200\ut{m}}{6.509\ut{s}}+19\ut{km/h}\cdot \frac{1000\ut{m}}{1\ut{km}}\cdot \frac{1\ut{h}}{3600\ut{s}}} \\&= \frac{4686480}{843671}\ut{s} \\&\approx 5.55486676678..

(a) t=1s $$ x(1) = 3(1) - 4(1)^2 + (1)^3= 0\ut{m}$$ (b) t=2s $$ x(2) = 3(2) - 4(2)^2 + (2)^3= -2\ut{m} $$ (c) t=3s $$ x(3) = 3(3) - 4(3)^2 + (3)^3= 0\ut{m} $$ (d) t=4s $$ x(4) = 3(4) - 4(4)^2 + (4)^3= 12\ut{m} $$ (e) $$ \begin{aligned} \Ans &= \Delta x = x(4)-x(0) \\ &= 12\ut{m}- \bra{3(0) - 4(0)^2 + (0)^3} \\ &= 12\ut{m} \end{aligned} $$ (f) $$ \begin{aligned} \Ans &= \frac{\Delta x}{\Delta t} ..

$$ \begin{cases} v_1 &= 35\ut{km/h} \\ v_2 &= 60\ut{km/h} \\ S &= S_1 = S_2 \end{cases}\\ $$ $$ \begin{aligned} \Ans &= \bar v = \frac{\Sigma S}{\Sigma t} = \frac{S_1+S_2}{t_1+t_2} \\ &= \frac{2S}{\frac{S}{v_1}+\frac{S}{v_2}} \\ &= \frac{2}{\frac{1}{v_1}+\frac{1}{v_2}} \\ &= \frac{2v_1v_2}{v_1+v_2} \\ &= \frac{2 \cdot 35\ut{km/h} \cdot 60\ut{km/h} }{35\ut{km/h} +60\ut{km/h} } \\ &= \frac{840}{19..

$$ \begin{cases} S &= 2.80\ut{km} \\ v_1 &= 6.00\ut{km/h} \\ v_2 &= -7.70\ut{km/h} \\ \Sigma t &= 35.0\ut{min} = \frac{35}{60}\ut{h} \end{cases} $$ $$ \begin{cases} t_1 &= \frac{S}{v_1} = \frac{2.80\ut{km}}{6.00\ut{km/h}} = \frac{28}{60}\ut{h} \\ t_2 &= \Sigma t - t_1 = \frac{35}{60}\ut{h} - \frac{28}{60}\ut{h} = \frac{7}{60}\ut{h} \end{cases} $$ (a) $$ \begin{aligned} \Ans &= \bar v = \frac{\Si..

(a) $$ \begin{cases} v_1 &= 1.22\ut{m/s} \\ v_2 &= 3.05\ut{m/s} \\ S_1 &= S_2 = S = 73.2\ut{m} \end{cases} $$ $$ \begin{aligned} \\ \Ans &= \bar v = \frac{\Sigma S}{\Sigma t} = \frac{S_1+S_2}{t_1+t_2} \\&= \frac{2S}{\frac{S}{v_1}+\frac{S}{v_2}} = \frac{2}{\frac{1}{v_1}+\frac{1}{v_2}} \\&= \frac{2v_1v_2}{v_1+v_2} \\&= \frac{2\cdot1.22\ut{m/s}\cdot 3.05\ut{m/s}}{1.22\ut{m/s}+3.05\ut{m/s}} \\&= \fr..

(풀이자 주 : 트레드밀 = 러닝머신) (a) 트레드밀 위 이므로 변위=0 (b) 변위=0 이므로 평균속도=0