Question

How do you tell if mechanical energy is conserved in an experiment?

i’m doing a lab analysis but i don’t understand how mechanical energy works at all, much less if it’s conserved or not

Answer 1

To determine if mechanical energy is conserved, calculate the sum of kinetic and potential energy at two points and check for equality, ensuring no nonconservative forces are at work on the system.

Step-by-step explanation:

To determine if mechanical energy is conserved in an experiment, you must analyze the types of energy present and the work being done on or by the system. Mechanical energy is conserved when the sum of kinetic energy (K) and potential energy (U) at the initial point (i) is equal to their sum at the final point (f), expressed as Ki + Ui = Kf + Uf. This is true only if there are no nonconservative forces, like friction or air resistance, doing work on the system. If such forces are present, then mechanical energy will not be conserved, and you will need to account for the energy lost to these forces.

Strategy to check for conservation of mechanical energy:

1. Identify the system and sketch it if necessary.
2. Determine all forces acting on the system and whether they do work.
3. Label each force as conservative or nonconservative.
4. If nonconservative forces are doing work, mechanical energy is not conserved. Consider the energy transferred to other forms like heat or light.
5. Perform calculations using the correct units for work or energy to ensure results are in joules.
6. Check your answer to make sure it makes sense both mathematically and physically.