The average acceleration can be calculated using the formula:
\[ \text{Average acceleration} = \frac{\text{Change in velocity}}{\text{Time taken}} \]
The change in velocity is the final velocity minus the initial velocity. Here, the roller coaster starts from rest, so the initial velocity is 0 m/s, and the final velocity is 25.5 m/s. The time taken is 2.8 seconds.
So, the average acceleration is:
\[ \text{Average acceleration} = \frac{25.5 \, \text{m/s} - 0 \, \text{m/s}}{2.8 \, \text{s}} \]
\[ \text{Average acceleration} = \frac{25.5 \, \text{m/s}}{2.8 \, \text{s}} \]
\[ \text{Average acceleration} ≈ 9.11 \, \text{m/s}^2 \]
Therefore, the average acceleration of the roller coaster is approximately \( 9.11 \, \text{m/s}^2 \).
