Ok so we know:
The time (t) is 18seconds
The acceleration (a) is 2.2m/s2
The displacement (r) is 660
Using the equation

With 'u' being the initial velocity we want, we get:

So:

So:

So the original/initial velocity was 16.8666 or 16.87 m/s
Hope this helped
Is that on the question or ?
The centripetal acceleration of the car is 48,800 mi/h2
Solution :
Given :
Mass of the object attached to the spring, m = 2 kg
Velocity of the object as it moves, V = 5 m/s
Amplitude of the object as it swings, A = 2.5 m
We have to find the frequency of the object.
We known,

Therefore, 

f = 0.32 Hz
Therefore the frequency of the object is 0.32 hertz when the amplitude of the 2 kg mass is 2.5 m moving a speed of 5 m/s.
I don't really feel like doing the work, but in essence you have to find the y-component of the water's velocity and subtract that from 4