Answer:
38 mpg
Step-by-step explanation:
Initial efficiency = 39 mpg
Initial speed = 40 mph
Final speed = 50 mph
The efficiency drop between 40 mph and 50 mph is given by:
[tex]E_d = 0.1 \frac{mpg}{mph}*\Delta V[/tex]
The total efficiency drop from 40 to 50 mph is:
[tex]E_d = 0.1 \frac{mpg}{mph}*(50-40)mph\\E_d = 1\ mpg[/tex]
Therefore, the efficiency at 50 mph is:
[tex]E_{50} = E_{40} -E_d\\E_{50} = 39 -1\\E_{50} = 38\ mpg[/tex]
