In the amusement park ride known as Magic Mountain Superman, powerful magnets accelerate a car and its riders from rest to 42 m/s (around 90 mi/h) in a time of 8.1 s. The mass of the car and riders is 4800 kg. Find the average net force exerted on the car and riders by the magnets. my solution: first i calculated the acceleration which is 5.19m/s squared. then i used F=ma, and that gave me 24,912kg m/s squared. am i correct?