Answer:
D. 59.23 m
Step-by-step explanation:
Given that:
initial height
of the roller coaster = 200m
speed (v) = 40 m/s
use conservation of energy between starting height and top of loop

where
i.e the final height = 2R
R = radius of the loop
Then

Divide both sides with m; we have :


1962 = 800 + (9.81 )(2R)
1962 -800 = (9.81 )(2R)
1162 = 19.62 R

R = 59.23 m