The Physics of Running into Stuff
Please enjoy this video demonstration.
(Note: even if I were to fail this project, I still got to see my mom run into a wall and that is worth all of the A's in the world).
Let's break it down one more time.
Let's break it down one more time.
Here we see my mom at velocity=0, albeit looking quite dubious. Her Normal Force is equal to her Weight, so she is still.
As she approaches the wall, her velocity increases as her feet push back on the floor and the floor pushes her forward. She is transforming the chemical energy of her body into the mechanical energy of her muscles moving and doing Work, and losing a small amount of heat in the process.
As she reaches the wall, she is stopped by the wall. Her weight has nothing on the drywall and it stops her from plummeting through to our kitchen. She is no Hulk, no Kool-Aid Man. No! Kelly is a mere mortal, stopped by a wall just like the rest of us.
Thanks to Newton, we know that the wall applies a force equal and opposite to the one applied by her to the wall. As a result she is pushed back and stumbles a few feet backwards, unfortunately not losing her balance enough to fall. Unlike the example with Katherine, gravity is not as much of a factor unless there is a much larger velocity when approaching the wall that would cause the person to fall to the ground.
For your enjoyment: here is a video of me taking advantage of my mom's willingness to actually get to help me with a project for once.
"Yes, Mom, I really need this to get an A on my project!"
"Yes, Mom, I really need this to get an A on my project!"