Answer:
58.0 m/s
Step-by-step explanation:
We can solve the problem by using the following SUVAT equation:

where
v is the final velocity of the roller coaster
u = 13 m/s is the initial velocity
a = 4.0 m/s^2 is the acceleration
s = 400 m is the displacement
Substituting and solving for v, we find
