Here is an interesting video from the interwebs.
Yes, it is narrated in some language other than English (maybe Turkish?). Yes, it is not the best quality – it is like watching a good video with your eyes all squinted. But here are some questions:
Is this real or fake?
Is this even possible (in case it is fake)?
If this is real, I wonder what the first goat that did this was thinking: “hey. I bet you I can get down this ravine without dying.”
Why is the camera mostly still, but shakes just enough for me to have to adjust the coordinate system? Haven’t these people ever heard of a tripod?
Using Tracker Video, I can get the motion of that goat as it goes down the canyon (or whatever it would be called). I don’t know know the scale, but I will just guess that a goat is 1 meter long.
Here is the horizontal motion of the goat (distance units are in goats where 1 goat = the length of a goat)
Looks like a fairly constant velocity. This is what you would expect for a real jumping goat. When not in contact with the rock wall, the only force on the goat would be the gravitational force (which is down). This means that the only acceleration will be in the vertical direction.
For the vertical motion, the acceleration should be constant. Also, the acceleration for each jump should be the same. Here is the vertical motion of the goat.
Comparing the fitting equation to the kinematic equation (for constant acceleration), I get:
Here, it is important to note that the a in the parabolic fit is not the acceleration. To emphasize that this is different, I called the acceleration a y in the kinematic equation.
I have at least three jumps for the goat. Using the same ideas, I get the following three vertical accelerations:
-2.92 goat/s 2
-5.36 goat/s 2
-3.84 goat/s 2
That is not very consistent, but the video is fairly crappy. Suppose I take the average measured acceleration of about 4 goats/ 2. How big would this make the goat? I can assume that these are Earth-based goats jumping on Earth. If this is the case then the vertical acceleration should be about -9.8 m/ 2. This gives:
That seems like a pretty big goat. However, I admit that even defining the beginning and end of the goat was not easy. Also, there is an assumption that the frame rate of the video is in real time. It might be in slow motion for a better effect.
Well, let me just suppose that this is a real video and the new scale is correct. Some interesting questions:
How far apart are the two rock walls? Answer: around 8 goats or 20 meters.
How far vertically does the goat fall? Answer: The three ‘drops’ were 17, 13, and 16 meters.
How fast did the goat jump? Answer: using the horizontal distance and the time I get the first two jumps had a horizontal velocity of around 16 m/s. The third jump had a horizontal speed of around 17.5 m/s (ummm. that is like 40 mph)
I really don’t know if a goat can jump horizontally with a speed of around 40 mph. That seems crazy. Either this video is fake, or it is not playing in real time speed (I suspect the later). If it is indeed not in real time, I can’t really figure out the correct time without knowing a scale.
One more question. If the time scale is correct and the distances are correct, is this jump even realistically survivable by a human? I already answered this question before. Here is the simple answer. My Wolfram Alpha dangerous jumping calculator widget.
Using a jumping height of 16 meters and a landing distance of 0.5 meters, I get an acceleration of 300 m/s 2 or about 30 g’s. According to NASA’s g-force tolerance data, this wouldn’t really work for a human (maybe it would be ok for a zombie).
Conclusions – or tl;dr
The video is not great quality. For the first three jumps, the horizontal velocity is constant (as it should be). I get slightly different vertical accelerations for the three jumps (they should all be the same). This could be because it is fake or it could be due to the poor video quality. I suspect the problem is that the frame rate has been changed.
