Energy & Energy Transformations Review
Learning Goals – Physical Science 3 A (PS3A)
· List different forms of energy (e.g., thermal, light, chemical, electrical, kinetic, potential and sound energy).
· Describe ways in which energy is transformed from one form to another and transferred from one place to another (e.g., chemical to electrical energy in a battery, electrical to light energy in a bulb).
Energy is the ability to do work. We even say when we are tired and don’t want to work that we have low energy. Energy comes in many different forms including: heat, light, sound, electrical, kinetic (motion), potential (energy of position), and chemical. The law of the conservation of energy states that energy is never created or destroyed. However, energy can be transferred from one object to another and it can be transformed from one form of energy to another.
Energy Transformations in a Car
Energy transformations can be understood by looking no farther than a car. In the engine, the fuel (chemical energy) is burned in the cylinder. As the fuel burns, it creates hot gases (heat energy). The gases expand and press against the piston. Through a combination of rods, shafts, and gears, the piston is connected to the wheels of the car. The pressure of the expanding hot gases makes the piston move (kinetic energy). This causes the wheels to rotate and makes the car move (kinetic energy).
Not all the energy released when gasoline burns is transformed to kinetic energy. Most of it becomes heat energy. That is why the car needs a radiator to prevent it from overheating. Once the car is moving, the next important energy transformation comes when the car stops. Friction from the car’s brakes stops the car; in other words, it reduces the car’s kinetic energy. When the brake pads rub against the brake drums, the brakes get very hot (kinetic energy is being transformed to heat energy). By the time that a car stops, almost all the chemical energy stored in the fuel has been converted to heat energy.
1. Gasoline is what form of energy?
2. The moving car has what form of energy?
3. When you step on the brakes what energy transformation takes place?
Putting Wind to Work
The kinetic energy of wind starts from light energy. The light energy from the sun warms the earth’s atmosphere unevenly, causing air to...