To find the car's velocity while on the highway, we first need to calculate the final speed after the acceleration period.
- The initial speed of the car is 18 m/s.
- The car accelerates at a rate of 6 m/s² for 2.0 seconds.
Using the formula for final velocity:
\[ \text{Final velocity} = \text{Initial velocity} + (\text{acceleration} \times \text{time}) \]
Substituting the known values:
\[ \text{Final velocity} = 18 , \text{m/s} + (6 , \text{m/s}^2 \times 2 , \text{s}) \] \[ \text{Final velocity} = 18 , \text{m/s} + 12 , \text{m/s} \] \[ \text{Final velocity} = 30 , \text{m/s} \]
Thus, the car's velocity while on the highway is 30.0 m/s.