Teacher guide featuring 15 labs designed for Advanced Placement Physics 1.
Students use a photogate and dynamics system to explore how a cart's kinetic energy, gravitational potential energy, and total mechanical energy changes as it rolls down an inclined track.
How do the potential and kinetic energies of an object in a closed system change as its motion changes due to a conservative force? Design an experiment to explore how a cart's kinetic energy, gravitational potential energy, and total mechanical energy change as it rolls down an inclined track.
In the Structured version of this lab activity, students release a cart from several different heights on an inclined track and measure the different velocities of the cart, using a photogate, as it passes through a fixed reference point near the bottom of the track. Using their measurements of height, students calculate the cart's initial gravitational potential energy at the point from which the cart was released in each trial. Using both the speed and height of the cart at the reference point, students calculate the kinetic and gravitational potential energy of the cart at the reference point for each trial. Assuming that the total mechanical energy of the cart when it was released is equal to the cart’s initial gravitational potential energy, students compare that value to the sum of the cart’s kinetic and gravitational potential energy at the reference point. Student data should show that the total mechanical energy of the cart when it was released is equal to its total mechanical energy at the reference point. Students then use this equality to establish that the total mechanical energy of the cart system is conserved.
The Ohaus Scout Pro Balance 2000g listed in the Materials and Equipment section is for classroom use, not individual lab stations.
This experiment may require software and an interface for data collection.