m = mass of the car = 1500 kg
we know that 1 mph = 0.45 m/s
hence
v = speed gained by the car = 40 mph = 40 x 0.45 m/s = 18 m/s
since the car is gaining speed here , hence the energy need is same as the kinetic energy gained by the car
kinetic energy is given as
KE = (0.5) m v² where m = mass , v = speed
inserting the above values in the formula
KE = (0.5) (1500) (18)²
KE = 2.43 x 10⁵ J
we know that , 1 J = 2.78 x 10⁻⁷ kwh
hence
KE = (2.43 x 10⁵) (2.78 x 10⁻⁷)
KE = 0.068 kwh
hence the energy needed is 0.068 kwh
