To find the car's acceleration, we can use the following equation of motion:
v^2 = u^2 + 2as
Where: v = final velocity (0 m/s, as the car comes to rest) u = initial velocity (20 m/s) a = acceleration (unknown) s = distance covered (200 meters)
Plugging in the given values, the equation becomes:
0^2 = (20 m/s)^2 + 2a * 200 m
Simplifying the equation:
0 = 400 m^2/s^2 + 400a
Rearranging the equation to solve for acceleration (a):
400a = -400 m^2/s^2
a = (-400 m^2/s^2) / 400
a = -1 m/s^2
Therefore, the car's acceleration is -1 m/s^2. The negative sign indicates that the acceleration is in the opposite direction to the initial velocity, leading to the car coming to rest.