Since we have beginning velocity, time, and distance traveled, we can use this equation to find acceleration:

d = v_{i}t + ^{1}/_{2} at^{2}

Plug in 600 for d, 5 for v_{i} and 20 for t, then solve for a to find the acceleration

Once we have the acceleration we can use this equation to find the final velocity:

v_{f} = v_{i} + at

Plug in 5 for v_{i},, 20 for t, and use the acceleration found in part a to find final velocity