# Kinematics

Kinematics in regents is fairly easy and definitely helps with car crashes and measuring the different heights of things when you drop an object. equations like d= initial velocity times time + (1/2)(acceleration)(time^2) help when you drop an object with an initial velocity of zero on the earth and want to know how far it dropped assuming it landed and didn't blow up or explode or anything like that. For example if you explored some exotic planet with plants the size of skyscrapers and you wanted to find out how tall exactly it was if you measured how long it took for one of it's petals to fall, say it was 30 seconds and the planet had a known acceleration of 1.2 meters per second you could find out how tall it was by plugging in the numbers to the equation which would be 540 meters about the size of one of the World Trade Centers.

If instead you drop a 25 gram weight off of the world's tallest building, which is Burj Khalifa in the United Arab Emirates a country next to Saudi Arabia, you would know the distance of 829.8 meters, acceleration of 9,81 meters per second and the initial velocity would be 0. if you wanted to find the final velocity you would use (final velocity62)= (initial velocity)+ 2(acceleration)(distance). This would end up with the square root of about 16, 280 about 127 meters per second. Yet if we really did drop a 25 gram weight off a skyscraper would it really kill you? As the weight falls the faster it got the greater air resistance it would experience. Eventually the air resistance would equal out with the gravitational force ending the acceleration which means only in a vacuum would it reach the speed 127 meters per second. That is also how skydivers can jump off air planes and not die because of parachute increasing the air resistance.

These two videos are something I discovered while researching kinetics on You Tube. It talks about a different kinetics called rotational kinetics and though it goes into fuller depth explaining it with more videos, it connects a lot of the concepts we learned in regents physics to more places where we can use kinetics.

In the second video it starts out talking about how rotational kinetics can relate to linear kinetics and talks about centripetal acceleration which we learned as v62/R and how it relates to bridge equations. Bridge equations relate what you've learned in pre-calculus to the regents kinetics you've learned in Physics and builds a bridge between math and science. I found this fascinating because I could understand the basic ideas of something I haven't yet learned by using the previous knowledge I have and making connections.

## 1 Comment

## Recommended Comments