**Linear Motion**

background [prelab assignment (25 points) due at the begining of lab]

1. what is the basis of a motion detector probe / sensor?

2. sketch the relationship between graphs of

position versus time

velocity versus time

acceleration versus time

for (i) ball toss and (ii) car on track lab activity. align 3 graphs vertically, so able to relate their relative behavior

3. describe algorithm to generate the preceding graphs using data from a motion detector; i.e. numerical differentiation

4. statistical test to be used in this lab ? basis / rationale.

purpose

use of sensor & photogate

export data for Excel based analysis

analyze / describe / generate graphs

position versus time

velocity versus time

acceleration versus time

using the preceding resources, address the following goals

* for vertical motion (estimate the numeric value of g)

ball

picket fence

* and horizontal motion

track / cart; impact of sampling rate on data quality

develop your

groupcooperation / organization skills

materials

station 1: motion detector & cart / track - horizontal motion

station 2: motion detector & ball - vertical motion

station 3: photogate & picket fence - vertical motion

labquest = hardware / software for data collection; usb flash drive

software: Excel (for graphical analysis) and Mathematica (for statistical analysis)

methods / data analysis

student design

based on the Central limit theorem, as appropriate, each student in a group does their own data generation and subsequent analysis, then shares their results within a group

**content of lab report** [25 points; up to 2 weeks to work on lab report]

address the following aspects in the purpose of the lab

- impact of sampling rate on data quality

- using track / cart data [horizontal motion; 5 points]
- determine the value of g using the picket fence versus vertical ball toss [10 points]
- use statistics to compare the value of g using picket fence versus ball toss [5 points]
- error analysis [5 points]

**resources**

cart & track setup

picket fence

export data in LabQuest (as *.txt file) to computer using USB flash drive, then use Excel to open file for data analysis

vertical motion: free-fall lab with picket fence / photogate; lab with ball (and / or your hand) / motion detector

horizontal motion lab with track / cart setup

numeric differentiation: defn; algorithm

statistical tests: mathematica; recommend not using versions prior to Excel 2010 (1; 2)

analog to digital conversion considerations - see resources in earlier lab