To find the acceleration of the automobile, we can use the equation of motion that relates acceleration (a), initial velocity (u), final velocity (v), and time (t):
a = (v - u) / t
Given that the initial velocity (u) is 30 m/s, the final velocity (v) is 10 m/s, and the time (t) is 5 seconds, we can substitute these values into the equation:
a = (10 - 30) / 5
Simplifying the equation:
a = -20 / 5 a = -4 m/s²
Therefore, the acceleration of the automobile is -4 m/s². The negative sign indicates that the acceleration is in the opposite direction of the initial velocity, indicating deceleration or slowing down.