4-41 할리데이 10판 솔루션 일반물리학

$$\begin{cases} \phi &= 36.0\degree\\ d &= 0.900\ut{m}\\ v_0 &= 3.56\ut{m/s} \end{cases}$$ $$\begin{cases} \vec a &=-g\j\\ g &\approx 9.80665\ut{m/s^2}\\ \end{cases}$$ $$H = d\sin\phi$$ $$\begin{aligned} 2a\Delta y&=v_y^2-v_{0y}^2,\\ 2(-g)(d\sin\phi)&=(0)^2-(v_0\sin\theta_0)^2\\ \sin\theta_0&=\frac{\sqrt{2dg\sin\phi} }{v_0}\\ \end{aligned}$$ $$\begin{aligned} \theta_0&=\sin^{-1}\frac{\sqrt{2dg\sin\phi} }{v_0}\\ &=\sin^{-1}\(\frac{15}{89}\sqrt{5g\sin\phi}\)\\ &\approx 1.13092617946\ut{rad}\\ &\approx 1.13\ut{rad}\\ \end{aligned}$$