Reflection : 2
Educational Technology and Me as Physics Educator
Video Capturing based laboratory
What is the current Physics Lab Scenario ?
Passive participation of students while teacher and Lab attendant perform experiments .
No proper lab infrastructure in most of the schools and teachers rely on chalk and talk methodology to teach in Physics Experimental class .
Poor teaching methodologies
Result :
No development of Experimental skills among learners .
We are using Educational Technology like animations , simulations etc a lot while teaching Physics in Theory classes to make our lessons interesting but the awareness among students and teachers regarding the usage of technology in experimental physics is still in its infancy specially at school level .
We hardly use ICT skills in performing Physics experiments at school level . Thus I explored an ICT based method to conduct Physics experiments ie Video Based Lab ( VBL ) Method .
What is Video Lab Method ?
Taking observations and doing calculations from the video of the Physics experiment .
What we need ?
Video of the experiment which we want to study and software like logger Pro and Tracker .
Experiment - 1 : To study Projectile motion in the case of linear magnetic accelerator ie Gauss Rifle
Materials taken : Neodymium magnet , Nickel Plated Steel balls , Low friction track , Plastic Box , sand , meter scale , Digital camera and softwares like logger Pro and Tracker .
Theory
The Gauss Rifle
• When you release the first ball, it is attracted to the
first magnet. It hits the magnet with a respectable amount of force, and a
kinetic energy we will call "1 unit".
• The kinetic energy of the ball is transferred to the
magnet, and then to the ball that is touching it on the right, and then to the
ball that is touching that one.
• The third ball is now moving with a kinetic energy of 1
unit. But it is moving towards the second magnet. It picks up speed as the
second magnet pulls it closer. When it hits the second magnet, it is moving
nearly twice as fast as the first ball.
• The third ball hits
the magnet, and the fifth ball starts to move with a kinetic energy of 2 units.
It speeds up as it nears the third magnet, and hits with of 3 units of kinetic
energy. This causes the seventh ball to speed off towards the last magnet. As
it gets drawn to the last magnet, it speeds up to 4 units of kinetic energy.
Video
Analysis : The video camera is used
to collect position and time data , which can then be used to mathematically
and graphically model anything related to the position or motion of the object . By using frame
advance features and marking the position of a moving object in each frame ,
students are able to more precisely determine the position of an object at much
smaller time increments than with common timing devices such as photo gates ,
stop watches and mechanical dot timers .
Then the video is inserted in video analysis program which effectively collects , analyse and
report data and also enable the analysis of some situations that would not
otherwise be possible.
Several commercially available video analysis programs
such as Videopoint , Physics toolkit , logger Pro and Measurement in motion are used in Physics
instructional settings.
Execution
: Experimental Set Up :
• Use the two wooden
dowels to make a slide on which the magnets and balls will sit on and move down.
• Place the wood slide
on the table with the glued side down.
• Place the ball
bearings and magnets in the way shown in figure.
• Place one ball bearing
on the other side of the magnet,
about 5 cm from the magnet. This is the trigger ball.
• Pour the sand in the
plastic box and smooth it out so that
the sand is approximately level. Place
the box on the floor a couple of feet away from the edge of the table
Then giving a velocity to the initial ball the trigger
ball with very high velocity took a Projectile motion .
Observation
Method
: Using DSLR video of the various observations were taken . Video clips were downloaded
into logger pro for quantitative analysis of position data as a function of
time. The program will step through the movie one frame at a time and
when a marker is placed on the image in the frame (red dot), the x and y
coordinates of point will be entered in the data column, along with a time
corresponding to that frame of the movie. In addition, the point will be
placed in a plot that is created at the same time. When additional points
are added, the velocities of points are calculated, based
upon the time elapsed between movie frames and the distance between one point
and the next.
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Experimental Arrangement |
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Capturing Video |
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Data Collection and Result Analysis Using Logger Pro
Manual Readings
Range 2
- 48.5 cm
Range 3
- 52.5 cm
Average
range -
50.5 cm
By
video analysis
Range
- 51.5 cm
CONCLUSION :
I observed that students were finding this method more interesting then
conventional style of taking observations .
As now we have 21st
century tech savvy students so for them
working using videos and softwares is not a difficult task as compared to
earlier situation when they were not very good in computers and technology .
While working on softwares they also came across already installed videos like
that of projectile motion , free fall , pendulum etc so they explore another
way of studying Physics .
They were also guided that using this Video based Lab
( VBL ) they can gather data from real world situations which can then be
manipulated , analyzed and graphed in simpler way.
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