Q1. Explain the conservation of energy in terms of the energy transformation(s) that occur when you strike (light) a match. Q2. When you turn on a lamp at home you are using electricity generated by a power company or public utility. Assume the electricity powering the lamp was generated at a coal burning power plant and explain the conservation of energy in terms of the energy transformations that occur when you turn on the lamp. None
The Correct Answer and Explanation is:
Q1. Striking a Match – Energy Transformations and Conservation of Energy
When you strike a match, you are witnessing several energy transformations that illustrate the law of conservation of energy, which states that energy cannot be created or destroyed—only transformed from one form to another.
Initially, mechanical energy is used when you strike the match against the rough surface. This friction generates thermal (heat) energy due to the resistance between the match head and the striking surface. Once enough heat is produced, it triggers a chemical reaction in the match head, typically involving chemicals like potassium chlorate and sulfur.
As this reaction proceeds, chemical energy stored in the match head is released and transformed into thermal energy (heat) and light energy (visible flame). No energy is lost in the process—some is simply converted to heat, some to light, and some dissipates into the surroundings. The total amount of energy remains constant, illustrating conservation of energy.
Q2. Turning on a Lamp – Energy Transformations and Conservation of Energy
When you turn on a lamp powered by a coal-burning power plant, several energy transformations take place before you see light.
It begins with chemical energy stored in the coal. When coal is burned, this chemical energy is converted into thermal energy (heat), which is used to boil water and produce steam. The high-pressure steam then spins a turbine, converting thermal energy into mechanical energy.
The spinning turbine drives a generator, which converts the mechanical energy into electrical energy. This electricity travels through power lines to your home. When you turn on the lamp, the electrical energy is finally converted into light energy and thermal energy (as the bulb gets warm).
At every step, energy is transformed from one form to another, but the total energy is conserved—it’s neither created nor destroyed, only changed in form, demonstrating the law of conservation of energy.
