Math
posted by Anya .
Deceleration uniformly, a car traveling 25 m/s takes 10 seconds to come to a complete stop. What is the magnitude and direction of the car's acceleration as it slows down?
North at 2.5 m/s (2)
South at 2.5 m/s (2)
North at 9.8 m/s (2)
South at 25 m/s

You do not say if it was moving north or south when you hit the brakes.
Assuming it was going north and north is positive:
v = Vi + a t
0 = 25 + a t
a = 25/10 = 2.5
or 2.5 m/s^2 south