To find the maximum distance the electric car can travel at 70 miles per hour for 5.7 hours, you can use the formula:
\[ \text{Distance} = \text{Speed} \times \text{Time} \]
Substituting the given values:
\[ \text{Distance} = 70 , \text{miles per hour} \times 5.7 , \text{hours} \]
Calculating this:
\[ \text{Distance} = 70 \times 5.7 = 399 , \text{miles} \]
Thus, the maximum distance the fully charged electric car can travel at 70 miles per hour is 399 miles.