The final speed of the automobile, after accelerating for 10 seconds at 2 m/s² from an initial speed of 15 m/s, is calculated to be 35 m/s. This is found by using the formula v = u + at, yielding option (a) as the correct answer.
The final speed of the automobile can be calculated using the formula v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time. In this problem, the initial velocity u is 15 m/s, the acceleration a is 2 m/s², and the time t is 10 seconds.
Substituting these values into the formula, we get: v = 15 m/s + (2 m/s² × 10 s) = 15 m/s + 20 m/s = 35 m/s. Therefore, the final speed of the automobile is 35 m/s. after accelerating for 10 seconds at 2 m/s², the automobile's final speed is 35 m/s, which corresponds to option (a).