To find the net force acting on the roller coaster, we can use Newton's second law of motion, which states:
\[ \text{Force} = \text{mass} \times \text{acceleration} \]
In this case, the mass of the roller coaster is 2000 kg, and its acceleration is 2 m/s². Plugging in these values:
\[ \text{Force} = 2000 , \text{kg} \times 2 , \text{m/s}^2 = 4000 , \text{N} \]
Thus, the net force acting on the roller coaster is 4000 N.