To find out how far the Acela Express would travel in 8 hours, we first need to calculate its speed in miles per hour (mph).
The train traveled 775 miles in 5 hours:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} = \frac{775 \text{ miles}}{5 \text{ hours}} = 155 \text{ mph} \]
Now, to find out how far it travels in 8 hours:
\[ \text{Distance} = \text{Speed} \times \text{Time} = 155 \text{ mph} \times 8 \text{ hours} = 1240 \text{ miles} \]
Thus, the train would travel 1,240 miles in 8 hours.