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Back to HOME > WHY STUDY PHYSICS? =**DO INTERESTING THINGS IN PHYSICS by Audrey Yeoh, Year 12 Physics HL**= Everyone likes throwing balls but have you ever thought about the Physics going on during a ball toss? Here, we are going to analyze a simple ball toss experiment. media type="file" key="Movie on 2011-02-16 at 14.23 -2.mov" width="360" height="360"
 * Ball Toss Experiment - Kinematics**

In this video, a ruler, 23 cm, sawed off at the end, is used as a marker for the scaling of the analysis.

Using Loggerpro, a data analysis software, we are able to analyze the movie easily and swiftly.

We take the first point of which the ball leaves the hand and start plotting points to form a graph.

This is the result:



We can then move this data into excel where it can be further analyzed. This set of data will produce a Displacement- Time graph as below:
 * Time (s) || X (distance Traveled) || Y (Displacement from ground || Vx (horizontal Velocity) || Vy (Vertical Velocity) ||
 * 7.242 || 1.131 || 1.649 || 4.920 || 2.968 ||
 * 7.275 || 1.302 || 1.758 || 4.771 || 2.597 ||
 * 7.308 || 1.432 || 1.827 || 4.948 || 2.267 ||
 * 7.342 || 1.637 || 1.909 || 5.022 || 1.918 ||
 * 7.375 || 1.788 || 1.964 || 4.572 || 1.313 ||
 * 7.408 || 1.918 || 1.998 || 4.697 || 0.696 ||
 * 7.442 || 2.103 || 1.998 || 4.766 || 0.388 ||
 * 7.475 || 2.247 || 2.019 || 4.612 || 0.251 ||
 * 7.508 || 2.404 || 2.026 || 4.577 || -0.137 ||
 * 7.542 || 2.548 || 2.005 || 4.634 || -0.434 ||
 * 7.575 || 2.720 || 1.998 || 4.560 || -0.816 ||
 * 7.608 || 2.850 || 1.957 || 4.577 || -1.370 ||
 * 7.642 || 3.021 || 1.909 || 4.726 || -1.992 ||
 * 7.675 || 3.158 || 1.820 || 5.057 || -2.506 ||
 * 7.708 || 3.356 || 1.738 || 5.399 || -2.882 ||
 * 7.742 || 3.535 || 1.628 || 5.291 || -3.259 ||
 * 7.775 || 3.713 || 1.519 || 5.080 || -3.607 ||
 * 7.808 || 3.863 || 1.395 || 5.097 || -4.229 ||
 * 7.842 || 4.048 || 1.245 || 5.302 || -5.137 ||
 * 7.875 || 4.219 || 1.067 || 5.490 || -6.393 ||
 * 7.908 || 4.397 || 0.813 || 6.056 || -7.397 ||
 * 7.942 || 4.637 || 0.539 || 6.215 || -7.411 ||
 * 7.975 || 4.836 || 0.300 || 5.790 || -6.869 ||
 * 8.008 || 5.007 || 0.101 || 5.433 || -6.358 ||



With that, we can find the velocity and acceleration of the ball. Then this data can be further used to find the horizontal velocity the ball was released with, the angle of the release, the distance traveled, the time of the travel, the amount of energy it had... acceleration due to gravity is -9.8 to find horizontal velocity, we need to remove vertical velocity from the equation when v=0, the projectile has reached the maximum height of its motion this is approximately at 7.5s we need to subtract all times by 7.24 as that is starting time hence the ball reaches maximum vertical displacement about 0.25s in its flight we can then calculate its initial upwards velocity a=(v-u)t a=-9.8 v=0 u=? t=0.25 u=2.45m/s we know using the pythagerous theorem and velocity vectors that the intial horizontal velocity can be calculated from the vertical velocity and the initial velocity It will hence have a horizontal velocity of 16.8 m/s In theory, the horizontal velocity has 0 acceleration and the vertical velocity has an acceleration of 9.81 m/s^2 downwards hence if this holds through, then in the time period of 0.25s, the ball should travel a horizontal distance of4.19m However, this is not true in a real life scenerio due to air resistance as energy is lost in forms of heat and sound, not fully converted to kinetic energy In our video, the ball only travelled a distance of about 2.5m This means the efficiency of the throw is only about 60%, the same as a carnot engine. This experiment has not taken account of uncertainties and hence the result may not be entirely accurate.
 * time || Displacement || Velocity ||
 * Time (s) || Displacement (m/s) || Velocity (m/s) ||
 * 7.241666667 || 1.648859267 || 2.967969689 ||
 * 7.275 || 1.758445898 || 2.596971848 ||
 * 7.308333333 || 1.826937333 || 2.267069879 ||
 * 7.341666667 || 1.909127202 || 1.917763867 ||
 * 7.375 || 1.963920517 || 1.312754864 ||
 * 7.408333333 || 1.998166235 || 0.6963305 ||
 * 7.441666667 || 1.998166235 || 0.38811897 ||
 * 7.475 || 2.018713729 || 0.251135942 ||
 * 7.508333333 || 2.025562893 || -0.136983202 ||
 * 7.541666667 || 2.0050154 || -0.433780066 ||
 * 7.575 || 1.998166235 || -0.816190791 ||
 * 7.608333333 || 1.957071353 || -1.36983106 ||
 * 7.641666667 || 1.909127202 || -1.99196254 ||
 * 7.675 || 1.820088273 || -2.505649612 ||
 * 7.708333333 || 1.7378983 || -2.882353394 ||
 * 7.741666667 || 1.628311878 || -3.259056916 ||
 * 7.775 || 1.518725247 || -3.607221036 ||
 * 7.808333333 || 1.395440704 || -4.229352689 ||
 * 7.841666667 || 1.244759087 || -5.13686602 ||
 * 7.875 || 1.066681229 || -6.392543558 ||
 * 7.908333333 || 0.813262458 || -7.397086979 ||
 * 7.941666667 || 0.539296298 || -7.410785273 ||
 * 7.975 || 0.299575856 || -6.869131293 ||
 * 8.008333333 || 0.1009504 || -6.358298084 ||
 * time || Displacement || Velocity ||
 * Time (s) || Displacement (m) || Velocity (m/s) ||
 * 0 || 1.648859267 || 2.967969689 ||
 * 0.033333333 || 1.758445898 || 2.596971848 ||
 * 0.066666667 || 1.826937333 || 2.267069879 ||
 * 0.1 || 1.909127202 || 1.917763867 ||
 * 0.133333333 || 1.963920517 || 1.312754864 ||
 * 0.166666667 || 1.998166235 || 0.6963305 ||
 * 0.2 || 1.998166235 || 0.38811897 ||
 * 0.233333333 || 2.018713729 || 0.251135942 ||
 * 0.266666667 || 2.025562893 || -0.136983202 ||
 * 0.3 || 2.0050154 || -0.433780066 ||
 * 0.333333333 || 1.998166235 || -0.816190791 ||
 * 0.366666667 || 1.957071353 || -1.36983106 ||
 * 0.4 || 1.909127202 || -1.99196254 ||
 * 0.433333333 || 1.820088273 || -2.505649612 ||
 * 0.466666667 || 1.7378983 || -2.882353394 ||
 * 0.5 || 1.628311878 || -3.259056916 ||
 * 0.533333333 || 1.518725247 || -3.607221036 ||
 * 0.566666667 || 1.395440704 || -4.229352689 ||
 * 0.6 || 1.244759087 || -5.13686602 ||
 * 0.633333333 || 1.066681229 || -6.392543558 ||
 * 0.666666667 || 0.813262458 || -7.397086979 ||
 * 0.7 || 0.539296298 || -7.410785273 ||
 * 0.733333333 || 0.299575856 || -6.869131293 ||
 * 0.766666667 || 0.1009504 || -6.358298084 ||

Extra facts: Did you know that the ball is travelling at 100 times slower than the speed of sound, which is surprisingly also approximately the speed of a bullet? It is also travelling at a hundred thousand times slower than the speed of light. A human walks at a speed of 1.2m/s so the ball is travelling about 2.5 times faster than we can walk. Therefore it is always faster to throw a ball than to run with it in any ball game. This of course chages on a person's competency to throw a ball. This therefore concludes the Ball toss experiment.

The analyzing process is endless with countless properties that can be experimented with. Physics allows you to do these experiments, which sometimes may include shooting objects and levitating things. This is why you should choose Physics. It's fun, interesting and has a huge reach over many other subjects.