Final answer:
The initial speed of the car is 12.247 m/s.
Step-by-step explanation:
The car's initial speed can be determined using the equation:
v^2 = u^2 + 2as
Where v is the final velocity (which is 0 m/s since the car comes to a stop), u is the initial velocity (unknown), a is the acceleration (-5.00 m/s^2), and s is the distance traveled (15.0 m).
Plugging in the given values:
0 = u^2 + 2(-5.00)(15.0)
Simplifying and solving for u, we get:
u^2 = 150
u = ±12.247 m/s
Since speed is a scalar quantity, the initial speed of the car is 12.247 m/s.