Acceleration Due to Gravity Photogate and Picket Fence

ALDRIDGEsTATEhigh School

Physics ExperimentsInvestigating and Measuring Motion

SHORT EXPERIMENTAL INVESTIGATIONS 1

EXPERIMENT 1: Projectile Motion

Science Department

DATE SET:

DUE DATE :

Writing your Report

Once you have collected your data and analysed it, you can begin to compile your report. The outline and checklist for each of these sections is provided.

Projectile Motion – Video Analysis with “Logger Pro”

Aim:To examine the horizontal and vertical components of projectile motion,
To develop familiarisation with video analysis, and
To increase awareness of using gradients from graphs.

Equipment:Digital Video camera (or a digital still that can take digital footage in AVI format)
Photographic tripodmetre rulers (2)a ball (tennis ball or bigger)
(Note: the ball must not be light enough for the wind to have a significant effect on it)

Instructions:

1. Clear an area where the ball will be thrown – you will need about 5 to 8 metres.
2. Set up the camera at least 10m away (side on to where the ball will be thrown).
3. Set up the two rulers end to end directly under where the ball will be travelling.
4. Adjust the zoom on the camera until you have the whole throwing area in field of view – including the two metre rulers.
5. Record two throws of the ball – one throw should be a slow loopy throw, the other should be a bit flatter.
6. Download (“capture”) the video footage to the computers and use Logger Pro to analyse the videos as shown in class. You will need for your results:
7. a graph for each throw with horizontal and vertical position versus time,
8. a graph for each throw with horizontal and vertical velocity versus time. On each graph you should show the line of best fit as described below…
9. the horizontal and vertical acceleration for each throw is determined by the gradient of the line of best fit:
10. Select the points on the graph you want the computer to use for the line of best fit.
11. Select Analyse/Linear Fit.
12. Right click in the data box for the linear fit. Choose “Linear Fit Options…” and check “Slope” under “Standard Deviations”.

Questions/Analysis:

Q1.What do you notice about the vertical acceleration (or “y” acceleration)for each throw?

Q2.What do you notice about the horizontal (or “x” acceleration for each throw?

Q3.How does this acceleration compare with the acceleration due to gravity on an object falling straight down?

Q4.Calculate the error in the acceleration for each throw

Research:

Q5.The initial velocity of the ball is found from the vector addition of the horizontal (or “x”) velocity and the vertical (or “y”) velocity. Find out how to do a vector addition and determine the initial velocity of the ball for both the throws.

Q6.There is a fairly simple formula to predict the maximum height of a projectile from the initial velocity of the projectile and its angle of elevation. Find this rule and use it to predict the maximum height from the velocities found in part a.

C:\DOCUME~1\WaldingR.005\LOCALS~1\Temp\Proj Motion - Video Analysis.doc

ALDRIDGEsTATEhigh School

Physics ExperimentsInvestigating and Measuring Motion

Standards associated with exit criteria

• reproduction and interpretation of complex and challenging concepts, theories and principles

• reproduction and interpretation of complex or challenging concepts, theories and principles

• reproduction of concepts, theories and principles

• reproduction of simple ideas and concepts

• reproduction of isolated facts

• comparison and explanation of complex concepts, processes and phenomena

• comparison and explanation of concepts, processes and phenomena

• explanation of simple processes and phenomena

• description of simple processes and phenomena

• recognition of isolated simple phenomena

• linking and application of algorithms, concepts, principles, theories and schema to find solutions in complex and challenging situations.

• linking and application of algorithms, concepts, principles, theories and schema to find solutions in complex or challenging situations.

• application of algorithms, principles, theories and schema to find solutions in simple situations.

• application of algorithms, principles, theories and schema.

• application of simple given algorithms.

• formulation of justified significant questions/hypotheses which inform effective and efficient design, refinement and management of investigations

• formulation of justified questions/hypotheses which inform design and management of investigations

• formulation of questions and hypotheses to select and manage investigations

• implementation of given investigations

• guided use of given procedures

• assessment of risk, safe selection and adaptation of equipment, and appropriate application of technology to gather, record and process valid data

• assessment of risk, safe selection of equipment, and appropriate application of technology to gather, record and process data

• assessment of risk, safe selection of equipment, and appropriate application of technology to gather and record data

• safe use of equipment and technology to gather and record data

• safe directed use of equipment to gather data

• systematic analysis of primary and secondary data to identify relationships between patterns, trends, errors and anomalies.

• analysis of primary and secondary data to identify patterns, trends, errors and anomalies.

• analysis of primary and secondary data to identify obvious patterns, trends, errors and anomalies.

• identification of obvious patterns and errors.

• recording of data.

• analysis and evaluation of complex scientific interrelationships

• analysis of complex scientific interrelationships

• description of scientific interrelationships

• identification of simple scientific interrelationships

• identification of obvious scientific interrelationships

• exploration of scenarios and possible outcomes with justification of conclusions/ recommendations

• explanation of scenarios and possible outcomes with discussion of conclusions/ recommendations

• description of scenarios and possible outcomes with statements of conclusion/ recommendation

• identification of scenarios or possible outcomes

• statements about outcomes

• discriminating selection, use and presentation of scientific data and ideas to make meaning accessible to intended audiences through innovative use of range of formats.

• selection, use and presentation of scientific data and ideas to make meaning accessible to intended audiences in range of formats.

• selection, use and presentation of scientific data and ideas to make meaning accessible in range of formats.

• presentation of scientific data or ideas in range of formats.

• presentation of scientific data or ideas.

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