Answer:
37.5 m/s
Step-by-step explanation:
Using the law of conservation of energy, potential energy equals kinetic energy hence
![mgh=0.5mv^(2)](https://img.qammunity.org/2021/formulas/physics/middle-school/9u5wg1ed6alboxdlhs8o0x5e2zkzbye8xl.png)
Therefore
![v=√(2gh)](https://img.qammunity.org/2021/formulas/physics/college/gxilsz3zlf320pmeovi24xonp5h2lv20v6.png)
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
![v=√(2* 9.8* 71.6)=37.48055496 m/s\approx 37.5 m/s](https://img.qammunity.org/2021/formulas/physics/middle-school/syr7x9tzk93z57ahntl5wa870kxkw4x3on.png)