Picture in your head two athletes about to collide head-on on the playing field/court/pitch.
Anticipating the impact, the athlete drops his/her shoulder and balls his/her fists together at mid-thigh level. Upon contact, the athlete lifts upward as his/her forward momentum carries them forward.
Is it possible to estimate energy levels for the impact?
Let's give it a whirl.
Since energy is force-through-a-distance, we can get close if we have proxies for both of those quantities.
According to the CDC growth charts:
- 5th percentile 17 year-old girl weighs 96 pounds
- 95th percentile 17 year-old girl weighs 175 pounds
- 5th percentile 17 year-old boy weighs 112 pounds
- 95th percentil 17 year-old boy weighs 187 pounds
According to Kilgore's strength standards, a "physically active":
- 125 pound, 17 Y-O girl can dead-lift 37 pounds
- 175 pound, 17 Y-O girl can dead-lift 53 pounds
- 125 pound, 17 Y-O boy can dead-lift 98 pounds
- 200 pound, 17 Y-O boy can dead-lift 171 pounds
I chose the dead-lift values because the motion described in the intro very nearly replicates the motion of a dead-lift so the forces should be very good proxies for what would happen on the field. These values will be used as the "Force" in our Force * Distance calculations.
According to Ergonomic Human Measurement Tables, the distance from the ground to the tops of the shoulders:
- 5th percentile woman 48.8 inches
- 95th percentile woman 56.4 inches
- 5th percentile man 52.8 inches
- 95th percentile man 60.8
Whlle the height of the shoulders is not directly related to the amount of energy that will be generated, it is a reasonable proxy for the distance the doubled-fists will travel as long as we look at RELATIVE numbers.
If you "normalize" the 5th percentile woman as "1.0" then all of the other numbers will be the multiple quantifying how much greater the force generated by the other cells in the matrix.
Energy, first order calculations:
- 5th Percentile, 17 Y-O girl 1.0 (Let's name her "Olivia")
- 95th Percentile, 17 Y-O girl 1.7 (Hannah)
- 5th Percentile, 17 Y-O boy 2.9 (Ashok)
- 95th Percentile, 17 Y-O boy 5.8 (Biff)
So in a collision between Olivia and Hannah, Hannah can deliver 70% more energy to Olivia than Olivia can deliver to Hannah.
In a collision between Hannah and Ashok, Ashok can deliver 70% more energy to Hannah than Hannah can apply to Ashok.
In a collision between Ashok and Biff, Biff can deliver 100% more energy to Ashok than Ashok can apply to Biff.
And in a collision between Olivia and Biff, Biff can send Olivia into orbit with 480% more energy than Olivia can deliver to Biff.
* "Physically active" according to Kilgore : A person who exercises or plays a sport(s) at least three times a week for more than 45 continuous minutes each session. No goal or programming of exercise need be apparent. Activities done during work hours and household chores are not relevant to this definition (neither are accumulated steps, i.e. step counting).
That's pretty complicated and I'm not sure I followed it correctly. I just know that if I had to compete with girls I'd only want it to be wrestling.---ken
ReplyDeleteWhat happens when we add in velocity?
ReplyDeleteBoys: Teenage boys, particularly those involved in competitive sports, can run the 40-yard dash in the 5.0 to 6.0-second range by the time they reach high school. By the end of their teens, top-performing athletes may record times as low as 4.5 to 4.8 seconds, especially in sprint-heavy sports like football or track.
Girls: Teen girls tend to run the 40-yard dash in the 6.0 to 7.0-second range. Athletic training and puberty help improve their performance, but there may be a wider range of times depending on the level of sports involvement. Source Bit Creature.