To find the value of 'v', we can use the formula for velocity:

velocity = distance / time

Given values:
Initial distance (S) = 900
Final distance (s) = 225
Initial velocity (v) = 40

We can calculate the time taken for the object to travel from S to s:

Time = (s - S) / v
Time = (225 - 900) / 40
Time = -675 / 40
Time = -16.875

Now, we can use the formula to find the final velocity (v):

v = (s - S) / Time
v = (225 - 900) / -16.875
v = -675 / -16.875
v = 40

Therefore, the final velocity (v) is 40.