Answer:
37.5 m/s
Explanation:
Using the law of conservation of energy, potential energy equals kinetic energy hence
[tex]mgh=0.5mv^{2}[/tex]
Therefore
[tex]v=\sqrt{2gh}[/tex]
where g is the acceleration due to gravity, m is the mass of the object, h is the height and v is the speed of the roller coaster
Taking g as 9.81 then
[tex]v=\sqrt{2\times 9.8\times 71.6}=37.48055496 m/s\approx 37.5 m/s[/tex]