Answer:
The speed  of roller coaster at the ground is 41.6 m/s.
Explanation:
mass of roller coaster, m = 756.5 kg
height, h = 88.2 m
(a) Let the speed of car at the ground is v.
Use conservation of energy
Potential energy at height = kinetic energy at bottom
[tex]m gh = \frac{1}{2}mv^2\\\\9.8\times 88.2= 0.5\times v^2\\\\v = 41.6 m/s[/tex]