video used by students to learn. the video were recoded into mp4 format, frame size same as original using any video converter http://any-video-converter.com/products/for_video_free/
can't figure out where the video came from, trying to attribute the authors, i[s]f you know, please post them.[/s] http://jabryan.iweb.bsu.edu/videoanalysis/index.htm
http://jabryan.iweb.bsu.edu/videoanalysis/BouncingBall.doc Conservation of Energy - Bouncing Ball
Mark the position of this 305 g ball as it falls and bounces four times. Then paste this data into a spreadsheet.
Delete the horizontal position values since they are not relevant to our needs.
Use the meter stick taped to the right door frame in the video for scaling purposes.
Translate the origin to the lowest position marked in any frame so that the floor will be the zero reference point for potential energy.
Plots of position-time, velocity-time, and acceleration-time are useful. Also of interest will be a force-time graph, where force is calculated by applying Newton’s 2nd Law to the acceleration values (F = ma).
The position-time plot will be “piecewise” quadratic and have one-half the value of the acceleration due to gravity as its square term coefficient (i.e., y = 4.9x2).
The velocity-time graph will be “piecewise” linear and have the acceleration due to gravity as the slope of each section.
The acceleration-time plot should be “piecewise” constant, with “spikes” at each bounce.
You can cut and paste portions of this data into new spreadsheet columns and graph the results to obtain equations that give the acceleration of the ball as it rises and falls.
A gravitational potential energy-time plot can be made by direct calculation of the position data (PE = mgh).
Once velocity values are known, a kinetic energy-time plot is easily made (KE = 0.5mv2).
Paste the two energy columns side by side in a new spreadsheet and manipulate the next column so that it gives their sum (Total Mechanical Energy = Gravitational Potential Energy + Kinetic Energy).
You now have data for potential energy, kinetic energy, and total energy of the falling and bouncing ball. Plot each of these on the same graph for emphasis.
You can now evaluate how much energy was either lost or conserved in each bounce.
Each of these four video clips shows one moving cart colliding with a stationary cart.
Using DataPoint, you will need to mark one of the carts, copy and paste that data into a spreadsheet, then go back to DataPoint, mark the other cart, and paste that data into the spreadsheet next to the first cart’s data.
Make sure that the times for each cart’s marks correspond to the other’s.
The y values have no use in any of these clips and may be deleted from the spreadsheet since all motion is horizontal.
It is probably best to position your origin at the leftmost position marked.
The meter stick in the foreground should be used for scaling.
Once you have positions marked for each cart, a position-time plot may be made.
Slopes of each line segment may be used to obtain each cart’s velocity before and after the collision.
Data in the spreadsheet should be manipulated in order to determine velocities.
Velocity-time graphs for each cart should also prove interesting.
Once the velocities of each cart are known, it is easy to make kinetic energy (KE = 0.5mv2) and momentum (p = mv) calculations.
For collisions, we always want to compare the total momentum and total kinetic energy before the collision with the totals after the collision. These sums can be easily computed using the spreadsheet.
Momentum is conserved in both elastic and inelastic collisions; kinetic energy is only conserved in elastic collisions. Therefore, the total momentum before the collision should be equal to the total momentum after the collision, but the total kinetic energy after the collision should be less than the total kinetic energy before the collision.