Exploring 2-Dimentional Motion and Vectors with Capstone’s Video Analysis Feature
Capstone includes a very powerful video analysis feature which can be used for comprehensive analysis of moving objects as well as to improve understanding. Short video clips from your smartphone can be easily imported and analysed with a range of tools. The movement of objects with a high contrast to a uniform background can be automatically tracked by the software.
A ball will be thrown in a parabolic arc and various tools will be used to analyze the motion. Note that the vertical and horizontal axes have been marked and a distance of 4.00 m has been measured. This will enable the software to translate from pixels to m:
As part of the analysis, the position of the ball in each frame is marked and the result is as shown below:
It is now possible to have the software generate various graphs such as position vs time and velocity vs time.
A graph of vertical position vs time is as shown below:
A graph of horizontal position vs time yields the following:
A graph of the vertical component of velocity vs time yields the following result:
Capstone also includes tools that improve understanding. For example, in the screen below, the vertical and horizontal components of velocity are shown for the ball as it flies through the air.
To make the display less cluttered and less confusing it is possible to mark the vectors at an interval other than every frame. Below the vectors are shown every third frame:
It is also possible to have a single vertical vector and a single horizontal vector appear and move with the ball as it goes through the air.
It is also possible to show the acceleration vector as shown below:
The fact that a few vectors do not point directly down is likely due to minor errors made when marking the position of the ball in various frames with a mouse.