A 1900-kg hybrid automobile which operates on ethanol fuel is equipped with a multipurpose motor-generator-flywheel. When the vehicle slows or stops, 51% of the kinetic energy is recovered as...

A 1900-kg hybrid automobile which operates on ethanol fuel is equipped with a multipurpose motor-generator-flywheel. When the vehicle slows or stops, 51% of the kinetic energy is recovered as electrical energy in the battery. When the IC engine is used to recharge the battery there is a 24% efficiency of converting chemical energy in the fuel to electrical energy stored in the battery. The vehicle slows from 70 MPH to 20 MPH.

Calculate:

(a) Electrical energy recovered in battery. [kJ]

(b) Mass of fuel needed to store same amount of energy in battery. [kg]