Both professionals and high school students can come to the same answer as to which generates more power.
Sport Science, the Emmy Award-winning TV series, hosted by John Brenkus, uncovers sports’ biggest myths and mysteries by using cutting-edge technology to measure momentum, friction and the laws of gravity.
One episode asks the question: which generates more power, an NFL running back or a diesel truck? The Sport Science crew recruited Buffalo Bills running back, Marshawn Lynch and a 6,700 lb truck to test the problem.
First, the crew strapped Marshawn Lynch with a breakthrough technology that uses wireless sensors to monitor the subject’s every move. Then, they put him in a harness attached to a 135 lb metal sheet topped with two 235 lb tires; a total of 585 lbs, about 2.6 times Lynch’s body weight. The Bills running back was able to pull the heavy load for five yards, but not without struggle. The technological equipment used calculated Lynch’s power-to-weight ratio as 573 watts per kilogram.
In order to match Lynch’s power-to-weight ratio, the 6,700 lbs and 325 horse power truck needs to pull about 17,000 lbs. They attached this weight in cement blocks to the truck, and Marshawn Lynch, himself, hopped into the truck and put the pedal to the metal. However, the truck didn’t budge. Instead, it just burned rubber. The truck maxed out at a power-to-weight ratio of 86 watts per kilogram. This means that Marshawn is almost seven times more powerful than the diesel truck.
It is astonishing that a man has been proven to be more powerful than a huge diesel truck. The Sport Science crew proved this using measurements from cutting edge technology, but how does this make sense in the realm of physics? The truth is, almost any high school student who has taken physics could prove that Marshawn Lynch is more powerful than the truck without using any expensive technology. However, the same answers are not reached using high school physics equations.
The definition of power is how much work is done in a certain amount of time (P=W/t). The definition of work is how much force is exerted over a certain distance (W=Fd). Lynch exerted some force over a distance of 5 yards. The force cannot be calculated without some sort of technology, because we don’t know Lynch’s acceleration, and force equals mass times acceleration (F=ma). Since Lynch did move the weight 5 yards, he did some amount of work. The truck however, exerted a force on the weight it was pulling, but since the weight didn’t move an inch, no work was done (W=F(0)=0). Since Lynch did some work on the weight he was pulling, he generated some amount of power, based on how long it took him to pull the weight 5 yards. Based on these basic laws of physics, the truck didn’t do any work, so it didn’t generate any power. Additional calculations could be made regarding friction forces, but it will still not be as accurate as the results generated by the Sport Science crew.
This result is based on physics laws that date back to Isaac Newton, and his laws of motion, which is primarily what high school physics students study. Since then, the study of physics has expanded tremendously, and there are tools to measure power generated even if no work is done. This is similar to the idea that a horse and an ant can do the same amount of work. A horse can move a thousand pounds of sand ten feet, and so can an ant. The only thing is the horse will do the work considerably faster; therefore the horse is more powerful. Even though the inner workings of this technology is unknown to most high school physics students, they could easily come to the conclusion that an NFL running back is more powerful than a diesel truck, simply by observing the experiment in action.
