Question

1. Discuss the types of energy transformations that are involved in the following devices or events. (For example, for (a) striking a match transforms the chemical energy in the match head into thermal (heat) and radiant (light) energy).

a. striking a match

b. windmill

c. microphone

d. flashlight

e. water behind a dam flowing past a turbine to generate electricity

Answer 1

a) - potential energy in the match itself (in the form of chemicals)
- friction by rubbing the match head against the paper creates heat on the match and paper. Heat is a form of energy
- heat on the match head helps to create a chemical reaction - a form of energy
- chemical reaction creates fire
- output of fire is heat, a form of energy

b) moving air is kinetic energy
air's kinetic energy is applied to the blades
the blades are attached to a rotor
air's kinetic energy is transferred from blade to rotor through a physical connection
the rotor turns, transferring the air's kinetic energy in to torque
torque is a form of mechanical energy
torque from the rotor is transferred by a shaft to a generator
the generator itself spins (torque)
the parts inside of the generator convert torque to electricity
electricity is a form of energy

c) initial kinetic energy to make the ball roll
rolling ball has kinetic energy
ball rolls off of table
gravity (form of energy) and kinetic energy from ball pull ball to the floor
some of the kinetic energy from falling ball is transferred to sound energy when connecting with floor
floor changes the direction of falling ball's direction, forcing it back up
ball hits floor again, transferring more kinetic energy in to sound energy
process repeats until all kinetic energy from ball is transferred in to sound energy
insufficient kinetic energy in ball to overcome the ball's tendency to stay at rest means ball won't move

d) sound energy connects with a diaphragm in microphone
sound energy is converted to a physical vibration - mechanical energy
mechanical energy from diaphragm is converted to electrical energy in side
electrical energy leaves microphone through wires

e) potential energy in battery is converted to electrical energy
electrical energy travels from positive side of battery
positive charge travels along the wire to the light bulb
electrical energy is converted to light energy
electricity must complete a circuit to make something work.
energy leaves light bulb and travels back to negative side of battery (the ground portion of the circuit)