Advanced Physics Through Inquiry 1 Teacher Guide

(PS-2848)

Teacher guide featuring 15 labs designed for Advanced Placement Physics 1.

Conservation of Mechanical Energy

Lab Summary

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.

Theory

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.

Method

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.

Sensors / Equipment Used:

Smart Gate

(PS-2180)

Photogate that can be connected to any PASPORT interface, has auxiliary port to daisy chain gates, double beams for accurate speed measurement, and a special photogate tape slot.

Photogate Brackets (2 Pack) -- IDS

(ME-9806)

The Photogate Bracket is designed to attach Photogate Head to PAStrack and Curved PAStrack.

PAScar (Set of 2)

(ME-6950)

A feature-rich dynamics cart for virtually friction-free motion on a dynamics track.

PAStrack

(ME-6960)

Connect two 0.5m length tracks and use with PAScars to study motion.

Track Rod Clamp

(ME-9836)

Fastens to the T-Slot of a Dynamics track and accepts a 1/2 inch rod.

Cart Picket Fences (2 Pack) -- IDS

(ME-9804)

Replacement photogate fences that mount on Dynamics Carts.

Angle Indicator

(ME-9495A)

Fastens to the T-Slot of a dynamics track with hanging brass plumb bob for angle indicator.

Dynamics Track End Stop (2 Pack)

(ME-8971)

Replacement end stops for the Dynamics Tracks.

Aluminum Table Clamp

(ME-8995)

This clamp with 6.5 cm grip width, accepts plain or threaded rods up to 1/2 inch or 1.25 cm.

45 cm Stainless Steel Rod

(ME-8736)

Non-threaded and non-magnetic lab rod.

Four Scale Meter Stick

(SE-8695)

A convenient measuring device that includes four different metric scales of various precision.

Ohaus Scout SKX Balance 2000g

(SE-8757B)

Combines range, resolution and low cost, making it ideal for the student science lab. 2000 g version.

Materials Used:

The Ohaus Scout Pro Balance 2000g listed in the Materials and Equipment section is for classroom use, not individual lab stations.

The Associated Bundle:

Advanced Physics 1 Starter Bundle

(PS-2815)

Equipment and sensor starter bundle for performing 8 experiments in the Advanced Physics through Inquiry 1 Teacher Guide.

Interface Required

This experiment may require software and an interface for data collection.