Sunshine ==> stored in plants
Eat the plants ==> energy stored as fat and glucose in the body
When needed, food energy ===> muscles.
Muscle energy ===> work, on the pedals
Mechanical energy into the pedals==> torque on the sprocket ==> tension in the chain ==> torque on the gear ==> spin the backwheel
Rotation of back wheel ==> friction with the ground ==> force against the ground ==> reaction force against the back tire ==> work, on the bicycle ==> bicycle accelerates
Bike moving, has kinetic energy ==> friction with the ground ==> front wheel rotates
Rotational energy of front wheel ==> friction between the tire and the rubber wheel of the dynamo
Rotational energy of the dynamo ==> converts to electrical energy inside
Eletrical energy flows through wires to light bulb
In the light bulb:
Electrical energy ==> light energy and heat energy