This experiment designed for use with PASCO Capstone software, is similar to a traditional mechanical equivalent of heat design; however, the objective is somewhat different. The purpose of this experiment is to facilitate a discussion among students about the types of energy in the system and the energy transfer which takes place throughout the process. Students use a Force Sensor to measure the force as the hanging mass is raised and lowered. The string connecting the sensor and the hanging mass is wrapped around a meter cylinder (brass or aluminum) in a spiral pattern. The sliding friction between the string and metal cylinder causes the cylinder to heat up. Each metal cylinder has a built-in thermistor which is used to monitor the real-time temperature of the cylinder.
Using the equation Q = mc (Δ)T, the change in thermal energy can be calculated. In addition, the string passes over the large pulley on the Rotary Motion Sensor for measurement of the string velocity as it is pulled. A power-time graph is created, since power is simply the product of the force and velocity. By integrating the power-time graph, the energy input can be determined. Students then compare the energy input to the increase in thermal energy in the metal cylinder and discuss other types of energy that are present in the system.
The three sensors used in the experiment (Force, Temperature and Rotary Motion) allow students to measure everything needed to complete their energy analysis of the system. In addition, all measurements and calculations can be viewed real-time in PASCO Capstone as the energy is being put into the system. Students will immediately understand how their work translates into the heating of the metal cylinder.
This product requires or recommends PASCO Capstone for data collection and analysis.