Math
posted by Anya on .
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

I think this problem has a figure given, but it can't be shown. Well I think it's ok.
Acceleration is equal to change in velocity over time. Note that is a vector quantity, so it is represented by magnitude and direction. In the problem, since it slows down, it is termed as deceleration. The deceleration of the car is equal to 25 m/s / 10s = 2.5 m/s^2.
Since I don't know what direction the car is initially traveling, the answer can be the 1st or 2nd choices. But if there is figure given, if the car initially travels South, it decelerates at North direction, or if the car travels North, it decelerates at South direction.
Hope this helps~ :)