Energy Transformation Worksheet | 5th Grade Science - Free Printable

Problem Analysis:

The task involves understanding and explaining the energy conversions involved in various examples provided in the table. Each example demonstrates a transformation of one form of energy into another, which is a fundamental concept in physics and engineering.

Solution Explanation:

#### 1. Rubbing our palms
- Energy Conversion: Kinetic energy to thermal energy.
- Explanation: When you rub your palms together, you apply mechanical force (kinetic energy) by moving your hands against each other. This friction causes the molecules in your skin to vibrate more rapidly, increasing their thermal energy. As a result, your palms feel warm due to the conversion of kinetic energy into thermal energy.

#### 2. Electric lamp
- Energy Conversion: Electrical energy to heat and light energy.
- Explanation: An electric lamp receives electrical energy from an electrical circuit. Inside the lamp, this electrical energy is converted into heat as the filament resists the flow of electrons. Some of this heat is then converted into light energy, which is emitted as visible light. This process is why incandescent bulbs emit both light and heat.

#### 3. Burning of wood
- Energy Conversion: Chemical energy to heat and light energy.
- Explanation: When wood burns, the chemical bonds within the wood are broken, releasing stored chemical energy. This energy is converted into heat, which raises the temperature of the surroundings, and light, which is emitted as flames. The combustion process is exothermic, meaning it releases energy.

#### 4. Steam engine
- Energy Conversion: Chemical energy of coal to heat energy to mechanical energy.
- Explanation: In a steam engine, coal is burned to release its chemical energy, which is converted into heat energy. This heat is used to boil water, producing steam. The expanding steam pushes pistons, converting the heat energy into mechanical energy, which drives the engine's motion.

#### 5. Electric cells in a clock
- Energy Conversion: Chemical energy to electrical energy to mechanical energy.
- Explanation: An electric cell (battery) stores chemical energy in its electrodes and electrolyte. When connected to a circuit, a chemical reaction occurs, converting the chemical energy into electrical energy. This electrical energy powers the clock mechanism, which converts it into mechanical energy to move the clock hands.

#### 6. Microphone
- Energy Conversion: Sound energy to electrical energy.
- Explanation: A microphone captures sound waves, which are mechanical vibrations in the air. These vibrations cause a diaphragm inside the microphone to move back and forth. This movement generates an electrical signal proportional to the sound wave, effectively converting sound energy into electrical energy.

#### 7. Hydroelectric dams
- Energy Conversion: Gravitational potential energy to kinetic energy to electrical energy.
- Explanation: Water in a reservoir behind a hydroelectric dam has gravitational potential energy due to its height above the ground. When the water is released, it falls and gains kinetic energy as it moves downward. This kinetic energy is used to spin turbines, which are connected to generators. The generators convert the mechanical energy of the turbines into electrical energy, which is then distributed for use.

Final Answer:

Each example demonstrates a specific energy conversion process. The solutions are summarized as follows:

- Rubbing our palms: Kinetic energy → Thermal energy
- Electric lamp: Electrical energy → Heat and light energy
- Burning of wood: Chemical energy → Heat and light energy
- Steam engine: Chemical energy → Heat energy → Mechanical energy
- Electric cells in a clock: Chemical energy → Electrical energy → Mechanical energy
- Microphone: Sound energy → Electrical energy
- Hydroelectric dams: Gravitational potential energy → Kinetic energy → Electrical energy

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