Ok so I have to apologize, this blog is no longer only Doctor Who. I've realized that, unfortunately, I'm running out of ideas with Doctor Who so while I think up some more I've decided to branch out a bit and write about the brand new CBS drama Scorpion. It's about a team of geniuses and I've seen physics in practically every episode.
That brings me to the episode I'm discussing. This one is the most recent and caught a little basic physics in it. So in this scene Walter- the main character and genius- is trying to figure out exactly where the car beneath must be positioned in order to allow him to fall into it from the side of a building without injuring himself. It ends up looking a little something like this.
Yeah, he falls right through the sunroof and manages to climb into the front seat unharmed. Even better, before he jumped he actually calculating out exactly how he had to fall. He said "You know what, I'm 30 feet above concrete! Give me time to think!...Quiet! I'm doing my calculations. Pull your car up two-and-a-half feet. Create a freefall, 9.8 meters per seconds squared. Hurry!... 4,000 newtons of energy to break a leg. I should be okay...".
Okay, to be honest, the first I noticed was when he said he would free fall at 9.8 m/s2. It's pretty basic physics, 9.8 m/s2 is the acceleration due to gravity on Earth. The next thing he does is calculate exactly how much of a force it will take to break a leg and how much force he will create when he lands on the car. First, I'm rather disappointed that they had him say "4,000 newtons of energy" since newtons are the basic unit of measurement for force, but I digress. Anyways, there is no way he weighs 899.24 lbs (4000 N converted to lbs) so this goes beyond just the force caused when he falls to the ground when influenced by Earth's gravitational pull. So its more likely that he is worried about impulse. The 30 foot fall would mean he would pick up speed as he feel. For example, if the fall took 4 seconds, and he started from rest (0 m/s), than (4 s)*(9.8 m/s2) = 39.2 m/s would be his final velocity on impact with the ground. Now its most likely he is concerned about the impulse when he hits the ground. Impulse is the change in momentum (mass*velocity) and also force*time. Given an initial velocity of 0, this would mean that the force when he hits the ground is equal to (mvfinal)/(t). Given a considerably small time of impact, its quite possible to great a force great enough to break his leg from that height. So how does he fix that? He has his friends move the car up so that when he falls, he falls through the sun roof and onto the center console. Not only does this shrink the falling distance a bit, but cars also have shock absorbers which would absorb some of the energy to create a quick up and down motion before bringing the car to rest. Thus, impact time increases and altogether the force on his body is reduced, preventing injury from the fall.
Altogether pretty cool! Don't worry, I'm not giving up on Doctor Who I just don't want to run out of ideas yet. Real quick, the first gif is from Doctor Who, the second Scorpion and I feel the need to point- as a disclaimer- that I own none of the images that I use and I never claimed to. Anyways, thanks for reading!