Conservation of Energy Lab: Elastic Potential Energy
The purpose of this lab is to determine the spring constant of a rubber band using Hooke’s Law and the law of conservation of energy.
For this lab you will determine the spring constant of a rubber band using the concept of forces as well as the concepts of energy. BE SURE TO KEEP YOUR RUBBER BAND AFTER CLASS IS OVER!!!
Part 1: Determining k with Forces (Hooke’s Law)
By attaching varying masses to the end of the rubber band and measuring its displacement, you must create a graph that could be used to determine the value of the spring constant. You CANNOT just plug in each value into Hooke’s Law formula; you MUST use the graph to determine the value of k.
Your lab report must include the following for this part:
1. A list of materials used and a short procedure for the experiment.
2. All the data collected during the experiment.
3. A graph of the data and an analysis of how the graph can be used to determine k.
4. An experimental value for the spring constant based on the graph.
Part 2: Determining k with Energy (Law of Conservation of Energy)
For this portion of the lab you will use the conservation of energy and the equation for elastic potential energy to determine the spring constant of the rubber band. You may use any method you like, but it must use the conservation of energy to solve for your k value.
Your lab report must include the following for this part:
1. A list of materials used and a short procedure for the experiment.
2. All the data collected during the experiment.
3. Analysis of the data showing how the spring constant, k, was calculated. This should include an average value for k based on all trials.
For your conclusion, compare your values for k from both parts and explain if the value you obtained makes sense given the nature of the rubber band. Explain which method gave you the most accurate answer and why. Explain how you could determine how far to pull the rubber band to hit a target 3.25 meters away from the top of desk. Do not do the calculations, just provide a summary of the steps and method you would use. As always include errors and improvements for the lab.