Question

What is the velocity of a rollercoaster at the bottom of a track that is 70.5 m high if it starts from rest?

Answer 1

Given

The height of the rollercoaster, h=70.5 m

Initial velocity is zero

To find

The velocity at the bottom

Explanation

Let the velocity be v

By conservation of energy,

Kinetic energy at the bottom is equal to the potential energy at the top

$\begin{gathered} \frac{1}{2}mv^2=mgh \\ \Rightarrow v=\sqrt{2gh} \\ \Rightarrow v=\sqrt{2\times9.8\times70.5}=37.17\text{ m/s} \end{gathered}$

Conclusion

The velocity is 37.17 m/s