Final answer:
Energy transformation when riding a bike involves converting chemical energy from food into mechanical energy that is used to turn the bike's wheels, which involves both rotational and translational kinetic energy.
Step-by-step explanation:
When a girl is riding bikes, energy transformation occurs as the wheel turns. The muscles of the rider convert the chemical energy from food into mechanical energy in the form of muscular work. This energy is then transferred to the pedals of the bike, which creates torque on the crankshaft and eventually turns the wheels of the bike. As the wheels turn, some of the mechanical energy is transformed into rotational kinetic energy in the wheels and translational kinetic energy of the entire bike as it moves forward.
Moreover, due to friction between the bicycle components and air resistance, some mechanical energy is also converted to heat, which can warm up the tires and other parts of the bike. This phenomenon is an example of energy transfer and transformation from one form to another and from one system to another, similar to the way light energy provides plants the means to create chemical energy.
It's important to note that while riding, the bike wheel exhibits both rotational and translational kinetic energy; however, if the bike were stationary and the front wheel was spinning, it would possess only rotational kinetic energy relative to the Earth.