Advanced Physics Through Inquiry 1 Teacher Guide

(PS-2848)

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

Simple Pendulum

Lab Summary

Students use a photogate and pendulum to determine the physical properties of a simple pendulum that affect its period, and then use their data to support a mathematical model relating period to pendulum arm length.

Theory

What variables affect the period of a pendulum? Determine the physical properties of a simple pendulum that affect its period.

Method

The Structured version of this lab activity is divided into three parts: Part 1 – Students build a simple pendulum using a pendulum bob and thread and then measure the period Tp of their pendulum while increasing the horizontal displacement of the pendulum bob in each trial. Ten periods are measured in each trial and averaged. A plot of the average period versus displacement will show a straight horizontal line. From that, students are expected to recognize that the period is constant regardless of the magnitude of initial displacement of the pendulum. Part 2 – Using the same setup as in Part 1, students measure the period of their pendulum while increasing the mass of the pendulum bob in each trial. Ten periods are measured in each trial and averaged. A plot of the average period versus mass will show a straight horizontal line. From that, students are expected to recognize that period is constant regardless of the magnitude of the pendulum bob mass. Part 3 – Using the same setup as in Part 1, students measure the period of their pendulum while increasing the pendulum arm length (length of thread used). Ten periods are measured in each trial and averaged. A plot of the average period versus pendulum arm length will show a curved, or non-proportional, relationship establishing that the period is affected by the length of the pendulum arm. Students then use their data to calculate √Pendulum arm length. A plot of the average period versus √Pendulum arm length will show a linear (proportional) relationship. Students are expected to recognize that the period is proportional to the square root of the pendulum arm length and use their data to support the actual mathematical relationship between period and pendulum arm length.

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 Pendulum Set

(ME-8752)

Set of four pendula (brass, plastic, wood, and aluminum) that are ideal for PASCO’s Photogate Head and Photogate Accessory in timing experiments.

Pendulum Clamp

(ME-9506)

Hang up to three pendula from precisely the same height.

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.

90 cm Stainless Steel Rod

(ME-8738)

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.

Black Thread (3 pack)

(ME-9875)

Black nylon thread.

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.

Other Equipment:

Scissors

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.