ANSWER
400,000 Joules (Option B)
Step-by-step explanation
Given:
![v=\sqrt{(2k)/(2000)}](https://img.qammunity.org/2023/formulas/mathematics/college/81zrlpyxow31hx6ivb6qy4a9pnu33zzbzj.png)
where
v = velocity of the roller coaster = 20 m/s
k = the kinetic energy of the roller coaster
Desired Outcome:
The kinetic energy (k)
Solve for the kinetic energy (k)
![\begin{gathered} 20=\sqrt{(2k)/(2000)} \\ 20=\sqrt{(k)/(1000)} \\ square\text{ }both\text{ }sides \\ (20)^2=(\sqrt{(k)/(1000)})^2 \\ 400=(k)/(1000) \\ cross-multiply \\ k=400*1000 \\ k=400,000\text{ }Joules \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/602v4qgvoey5atiztp5byoypsfjvc4amn9.png)
Hence, the kinetci