Scientific Method Experiment: Testing the Law of Conservation of Energy

📚 Quick Study Guide

• 💡 The Law of Conservation of Energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. Energy can neither be created nor destroyed but can be transformed from one form to another.
• 🔍 In a closed system, the sum of potential energy (PE) and kinetic energy (KE) is constant if only conservative forces are acting.
• 📝 Potential Energy (PE) due to gravity is given by: $PE = mgh$, where $m$ is mass, $g$ is the acceleration due to gravity (approximately $9.8 m/s^2$), and $h$ is height.
• 📈 Kinetic Energy (KE) is given by: $KE = \frac{1}{2}mv^2$, where $m$ is mass and $v$ is velocity.
• 🔥 In real-world experiments, some energy is often converted into thermal energy (heat) due to friction or air resistance, which can affect results.
• 🍎 The total mechanical energy (TME) is the sum of potential and kinetic energy: $TME = PE + KE$.
• 📐 When analyzing an experiment, compare the initial total mechanical energy with the final total mechanical energy to verify the conservation law. Any differences indicate energy loss due to non-conservative forces.

Practice Quiz

1. What does the Law of Conservation of Energy state?
   1. Energy can be created but not destroyed.
   2. Energy can be destroyed but not created.
   3. The total energy of an isolated system remains constant.
   4. Energy disappears over time.
2. Which of the following formulas represents potential energy (PE)?
   1. $PE = \frac{1}{2}mv^2$
   2. $PE = mgh$
   3. $PE = mc^2$
   4. $PE = \frac{GMm}{r}$
3. Kinetic energy (KE) is dependent on which two factors?
   1. Mass and height
   2. Mass and velocity
   3. Height and velocity
   4. Force and time
4. What happens to the total mechanical energy in a system where only conservative forces are acting?
   1. It increases.
   2. It decreases.
   3. It remains constant.
   4. It fluctuates randomly.
5. In a real-world experiment, what commonly causes energy loss?
   1. Perfect insulation
   2. Conservative forces
   3. Friction and air resistance
   4. Creation of new energy
6. What is the formula for Total Mechanical Energy (TME)?
   1. $TME = PE - KE$
   2. $TME = PE \times KE$
   3. $TME = PE + KE$
   4. $TME = \frac{PE}{KE}$
7. If the initial TME of a system is 100J and the final TME is 80J, what can you conclude?
   1. Energy was created.
   2. Energy was destroyed.
   3. 20J of energy was converted to other forms, like thermal energy.
   4. The Law of Conservation of Energy is invalid.