Given: The energy equivalent of one gallon of

Question

gasoline is 1.3 × 108 J.
A compact car has a mass of 847 kg, and its efficiency is rated at 18.1%. (That is, 18.1% of the input power available is delivered to the wheels.) Find the amount of gasoline used to accelerate the car from rest to 20.1 m/s. Answer in units of gal.

Answer 1

Compute the kinetic energy of the car at 20.2 m/s. (KE = MV^2/2)

Divide that energy by 0.181 to get the chemical energy needed to accelerate the car to that speed.

Divide the chemical energy requirement by 1.3*10^8 J/gallon to get the numner of gallons needed, X.

Answer 2

.013