Reflection : 2 Educational Technology and Me as Physics Educator

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. 

Experimental Arrangement 

Capturing Video

Gauss Rifle 

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 21^st 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.