Trinity Walton Club Activity Archive

ECI SOLO WEEK 1 FRIDAY

Energy Conservation Lab

LAB: PENDULUM EXPERIMENT

Lab Instructions

Materials Needed:

  • A string (about 1 meter long)
  • A small weight (like a metal washer or a small pendulum bob)
  • A protractor
  • A ruler or measuring tape
  • A stopwatch
  • A clamp or a stable support to hang the pendulum from
  • Graph paper (optional)

Procedure:

  1. Setup the Pendulum: 
  • Attach the weight to one end of the string. 
  • Secure the other end of the string to a stable support so that it can swing freely. 
  1. Measure the Length: 
  • Measure the length of the string from the point of suspension to the center of the weight. Record this length as it will be important for calculating potential energy. 
  1. Initial Potential Energy: 
  • Pull the weight to one side and measure the height from the lowest point of the swing (the point where the weight would be directly below the support) to the initial position. This height will be used to calculate the initial potential energy. 
  1. Release and Timing: 
  • Release the pendulum without pushing it (let it fall freely). 
  • Use the stopwatch to measure the time it takes for the pendulum to complete one full swing (back and forth). 
  1. Calculate Potential and Kinetic Energy: 
  • The potential energy (PE) at the highest point can be calculated using the formula: 

PE=mgh 

where m is the mass of the weight, g is the acceleration due to gravity (9.81 m/s²), and h is the height measured. 

  • The kinetic energy (KE) at the lowest point can be calculated using the formula: 

Ke = 1/2 mv2 

where m is the mass of the weight and v is the velocity of the weight at the lowest point. The velocity can be approximated by measuring the speed of the pendulum bob at the lowest point using the time period of the swing. 

  1. Observation and Analysis: 
  • Observe that at the highest points of the swing, the pendulum has maximum potential energy and minimal kinetic energy. 
  • At the lowest point of the swing, the pendulum has maximum kinetic energy and minimal potential energy. 
  • Note how energy is conserved and converted between potential and kinetic forms throughout the motion. 
  1. Optional: Graphical Representation: 
  • Plot a graph of the pendulum’s height versus time or its speed versus time to visually represent the energy conversion.