Answer:
D) 25 m/s
Explanation:
In order to solve this problem we must use the following kinematics equation.

where:
Vf = final speed [m/s]
Vi = initial speed = 0
a = acceleration = 5[m/s^2]
t = time = 5[s]
After 5 seconds the acceleration is equal to 5 [m/s^2]
Now replacing the values in the equation:
Vf = 0 + (5*5)
Vf = 25[m/s]
Answer:
Explanation:36.05 km
Given
First car travels
South
then turns and travels
east
Suppose south as negative y axis and east as positive x axis
So, 

Displacement is the shortest between initial and final point
Dispalcement
Displacement
Displacement
Magnitude 
Magnitude
F = 1/t
F = 1/0.5
F = 2Hz
Answer is 2Hz