Please provide right solution for given problem:
Problem: A car is traveling along a straight road at a velocity of +39.4 m/s when its engine cuts out. For the next 2.09 seconds, the car slows down, and its average acceleration is. For the next 5.08 seconds, the car slows down further, and its average acceleration is. The velocity of the car at the end of the 7.17-second period is +20.8 m/s. The ratio of the average acceleration values is = 1.95.
Part A: Find the velocity of the car at the end of the initial 2.09-second interval.
Please provide clear step by step solution with notes on concepts and equations being used for above problem.