Friday, February 8, 2013

Graphs Galore!

Our graphs showing the relationship between acceleration and mass. Also, the graphs showing the consistency of velocity during our trials.

Thursday, February 7, 2013

Experimental Conclusion

So the results are in! Here's our conclusion and error analysis.

Error Analysis:
·         We did three trials with each ball to eliminate any oddball scores(pun intended)

·         We also used the same angle for the mini launcher for each trial.
We could have done more trials with different varying weights to further decrease the error in our experiment.

We found that our hypothesis was correct. As the mass of the ball increases, the acceleration decreases.  This means that as the mass of the human cannonball increases, their acceleration decreases and thus the net must be closer to the cannon. We learned how to work different types of equipment and how to apply smaller scale experiments to the real world. Using this information, we can see the relationships between different factors, such as weight, acceleration, and velocity, and their effect on the flight of the human cannonball. 

The calculations behind a safe launch takes into account lots of different factors, such as the barrel angle, the wind speed, temperature, and more. Knowing the relationship between at least some of these factors helps us to understand in a more concrete way how one factor interlopes with the other. Knowing weight's relationship with the flight also helps us to understand forces effect on the body. The average human can experience around 8 g's before blacking out, while a human cannonball must experience 9-12 g's during their flight. A heavier person would experience less g's than a lighter person, as well as a decrease initial velocity, decreased horizontal distance, and a decreased vertical height at a constant angle and charge (or force used to launch the projectile).  The g forces can also be controlled through training, as the human cannonballs must be physically fit to withstand the force without blacking out. They are also trained in tensing their body properly to avoid blacking out. Overall, this experience gave us insight to a couple of the factors that influence the flight of the cannonball. 

As one can see, the human with the lower weight (shown in the first image) goes farther and higher than the human in the second image with a higher weight at a constant angle and charge. The person with the higher weight will also experience less g's, acceleration, starting velocity, and deceleration.

A further factor that is of importance is the calibration of the net in comparison to the launch, considering the factors discussed above. If not calibrated correctly, fatalities are sure to occur. We see this clearly in the tragic story of Evin Bale, who calculated his net using a test dummy that was saturated with water. The heavier weight of the test dummy led the crew to place the net farther away than the distance his true weight would travel. As one can see, weight plays an extremely important role in the safety of the human cannonball.

Experimental Hypothesis

So here's the hypothesis we hope to prove, the purpose of the whole experiment, and the procedure so that you can try it at home!

Hypothesis:   As the mass of the object being expelled increases, the rate of acceleration and velocity decreases.

Purpose:    To explore the real world application of Mass v. Acceleration in regards to human cannon balls and their limits on force so that they will not black out or die. We will use these results to see the way weight effects the acceleration of humans as they are launched from the cannon.

Materials: A laptop, a mini launcher, 3 different massed balls (we used 5g, 16g, and 2g), a calculator, something to catch the flying ball with(we used a bag), safety goggles


1.       Set up laptop, Photogate Mounting Bracket, mini launcher (30degrees) and ball catcher.

2.       Push mini launcher back to fist notch with a pencil and place a ball in

3.       Record the velocity and repeat two more times.

4.       Repeat steps 2 and 3 with remaining balls.

5.       Find average velocities by adding all of the velocities for each ball up and dividing by three

6.       Use the average velocity to calculate acceleration by using the formula v2=Vo2+2ax

Friday, February 1, 2013

The Ball-Launcher Experiment

 We have completed our first experiment, exploring the real life applications of cannon launching. We used a mini-launcher that was hooked up a photo-gate mounting bracket that read the velocity when the object left the launcher. The video below is a look at our procedure. Our conclusions will be posted soon.

A Brief History of the Human Cannonball

It is easy to associate the idea of a human cannonball with a picture of a typical of daredevil-stuntman.
 The truth is in fact, far more surprising  The very first human to be shot into the sky was no other than a 14 year old girl named Zazel, in London in 1817. She used elastic bands to propel herself into space. Now, most human cannon-ballers use compressed air instead. Air is released into the cannon, pushing the platform up to an abrupt stop, hurtling the individual forward. The farther a person needs to fly, the more forceful the push, and faster the acceleration. Typically, a human cannonball experiences 9 G's at take-off, and 12 when landing. Surprisingly  it is not the force of leaving the cannon that is the most dangerous part, but the landing. Human Cannonballs are forced to decelerate at alarming rates. Most either use a net or water to absorb the impact and slow them down to a stopping point. Without this, they would be forced to decelerate from their high rate immediately on impact, proving fatal in almost all cases. Most of theses stuntman aim for the back third of the net, absorbing the forward energy and bouncing them backwards at a safe distance. Calibration of the net in relation to the cannon is another extremely dangerous part of the cannon-baller lifestyle. If the net is not placed correctly, it is likely the stuntman will never fly again. Evin Bale fatally met this mistake, calibrating the distance with the assistance of a test dummy. Little did he know, his dummy had been saturated with water, throwing the weight off. He made his final flight, missed the net, and died later that day. 
Its easy to see that many complex components make up the flight of the human cannonball, and we aim to uncover and de construct all of them. Stay tuned as we explore the physics behind the mystery of these daring men and women.

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