(a) Energy conversion:
Chemical energy of battery → electrical energy → heat and light energy.
(b) Given,
Mass of a car, m = 500 kg,
Speed of car, v = 36 km/h = 10 m/s
Work needed to stop a car = K.E. of the car
Therefore,
K. E. = 1 /2 mv2
= 1 /2 × 500 × 102
= 25000 Joule
