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
To find the magnitude and direction of the car's acceleration as it slows down, we can use the formula:
acceleration = (final velocity - initial velocity) / time
First, let's find the final velocity. The car is traveling at 25 m/s and comes to a complete stop, so the final velocity is 0 m/s.
Using the given data, we can substitute the values into the formula above:
acceleration = (0 m/s - 25 m/s) / 10 s
Simplifying the expression, we have:
acceleration = (-25 m/s) / 10 s
This gives us:
acceleration = -2.5 m/s²
The negative sign indicates that the car's acceleration is in the opposite direction of its initial velocity. Since the car is initially moving forward, the acceleration is in the opposite direction, which is south.
So, the magnitude of the car's acceleration as it slows down is 2.5 m/s², and the direction is south.
Therefore, the correct answer is: South at 2.5 m/s².