Answer:
Speed at the bottom of the roller coaster = 49.79 m/s
Explanation:
A new ride being built at an amusement park includes a vertical drop of 126.5 meters. Starting from rest, the ride vertically drops that distance before the track curves forward.
We have to find the speed at the bottom.
Here the gravitational energy fully converts to kinetic energy, so we equate it.
Gravitational energy = 
Kinetic energy = 
= 

= 2479.4
Velocity, v = 49.79 m/s
To find the acceleration, we will use the formula
F=ma
Here the net force will be 40N (50 - 10)
F = ma
40 = 4a
40/4 = a
10 m/s^2 = a
Hope you understood !
The energy transferred to the spring is given by:

where
k is the spring constant
x is the elongation of the spring with respect its initial length
Let's convert the data into the SI units:


so now we can use these data inside the equation ,to find the energy transferred to the spring: