Physics Movie Project: Defying Laws of Physics in The Matrix

[zmalik595]

I hav a physics movie project and i hav to find how the movie defies the laws of physics using calculations/theories with examples from the scenes.

I chose the movie-The Matrix where the guy is dodging the bullets on top of the scene. Anyways, I was wondering what equation/theory I would use to defy the reason why a human being cannot dodge 18 bullets in a matter of 6-8 seconds.
Thanks

 

[Drakkith]

Hrmm...may I suggest the movie "The Core"? It has MANY incorrect things with physics lol.
The only reason I say that is because the matrix isn't "real life" in the movie. That is precisely why Neo CAN dodge bullets.

But it may not be a big deal anyways. You can choose multiple reasons, such as reaction time, applied force by muscles and how fast they can move bone, ETC. I think it may be a little difficult to do equations for the human body however, so again I recommend something like The Core, which has simpler things.

 

[zmalik595]

yea too late to switch movies as its due tmrw, but i figured out some stuff like the speed of the bullet, mass, distance and stuff but what kinematics equation would i use to prove that it is impossible to hit a bullet? and the avg. reaction time is 50-100 m/s. Thanks

 

[Drakkith]

yea too late to switch movies as its due tmrw, but i figured out some stuff like the speed of the bullet, mass, distance and stuff but what kinematics equation would i use to prove that it is impossible to hit a bullet? and the avg. reaction time is 50-100 m/s. Thanks

If you know the speed a bullet travels, and how far away (approximately) the two are, then you should be all set! What do you think the equation is? (Homework question, so I cannot just answer it for you.)

 

[zmalik595]

aight but WHICH equation do i use?

 

[Drakkith]

aight but WHICH equation do i use?

How do you find how long something takes to travel a certain distance? You already have the speed and the distance of the two objects, the only step left is to use those two to figure out the other. If a car travels 60 miles per hour, how long does it take to go 60 miles? It's the same equation for that and for your problem.

 

[zmalik595]

Would i use like the 3 kinematic equations? because I am still confused bro i just need to know which one.

 

[Drakkith]

Would i use like the 3 kinematic equations? because I am still confused bro i just need to know which one.

I'm sorry, I don't actually know what the equations for kinematics are without looking it up. Do you have one for determining the distance traveled for an object? Or how to determine speed?

 

[zmalik595]

http://www.physicsclassroom.com/class/1dkin/U1L6a1.gif
Those are the equations, don't know which to use

 

[KingNothing]

Well, let's start figuring that out. What variables do you know, and what do you want to find out?

 

[zmalik595]

Nerve Impulses=50-100m/s
Speed of Sound= 343 m/s
Speed of a bullet (handgun)= 400-475 m/s
Average mass= 16-22 grams
Distance=25-30 feet
Bullets Dodged=18
Time= 6 seconds (approx.)

I guess I am tryin to show that using one of the equations will prove that it is impossible to dodge a bullet using those variables.

 

[KingNothing]

So how long will it take the bullet to travel 30 feet? Is this time greater than or less than the reaction time?

 

[zmalik595]

yea that sounds right but i need the equation :) thx

 

[KingNothing]

You HAVE the equations. Let me ask you something. If I am moving 30 miles per hour in my car, and I have to travel 30 miles, how long will it take me? Use the same equation.

 

[Drakkith]

You don't even need all those variables. You have already stated that the average reaction time in a person is 50-100 ms. The mass of the bullet shouldn't have anything to do with determining if someone can dodge it or not. It is not accelerating or decelerating for our purposes.

Do you NEED to use the kinematic equations? You have enough data to figure this out without using those specific equations.

Edit: Look at your equations. You have one in there that includes distance, time, AND velocity based on acceleration. Some simple algebra can easily get you the time that you need.

 

[zmalik595]

my teacher said it's preferred to use those equations/

 

[zmalik595]

and what would i convert it to? 30/400= .075 but what units since i can't use m/s

 

[KingNothing]

Convert all your distances to one unit, then do the math.

 

[Drakkith]

and what would i convert it to? 30/400= .075 but what units since i can't use m/s

You can easily use m/s if you want to. Convert the distance in feet to meters instead. A google search for unit conversion table will yield plenty of tables to use to convert your units.

 

[zmalik595]

so acceleration for bullets=d/va
a=30/400
a=.075 m/s
acceleration for reflex

a=30/100
a=.30

.30>.075 so it is possible to dodge a bullet?
That's not what I am tryin to do, I am tweakin yo.

 

[Drakkith]

so acceleration for bullets=d/va
a=30/400
a=.075 m/s
acceleration for reflex

a=30/100
a=.30

.30>.075 so it is possible to dodge a bullet?
That's not what I am tryin to do, I am tweakin yo.

That isn't the right way to figure out acceleration. We can assume that the bullet has already accelerated to max or near max speed right after it leaves the barrel, so to prove or disprove your problem we can effectively ignore acceleration for now.
Convert 30 feet to meters first. (Can't use feet with m/s, so let's convert feet to meters, as it is easy) Then you can figure out the time it takes for a bullet to travel that distance. After that, we need to figure out if a human being can A: react fast enough, and B: move fast enough.

Edit: Ignore your kinematics equation for now and let's figure out your problem fist, then work the kinematics into it. Let's first find out how long it takes for a bullet traveling at 400 m/s to travel 30 feet.

 

[zmalik595]

30 feet=9.14 meters
T=V/D
400/9.14=43.76 sec

100/9.14=10.9 sec

So now what?

 

[Drakkith]

30 feet=9.14 meters
T=V/D
400/9.14=43.76 sec

100/9.14=10.9 sec

So now what?

T=D/V, not V/D.

For example, if I traveled at 2 m/s for 10 meters, how long did it take me to go that far?

T=10/2
T=5 seconds. At 2 m/s it takes me 5 seconds to travel 10 meters.

 

[zmalik595]

ok 9.14/400=.02285

9.14/100=.0914

Still makes no sense

 

[zmalik595]

It takes .02285 seconds to travel 30 feet, while it takes .0914 seconds for a human to respond?

 

[Drakkith]

ok 9.14/400=.02285

9.14/100=.0914

Still makes no sense

Why are you dividing 9.14 by 100?

 

[zmalik595]

9.14=D in meters
100=human reaction m/s
9.14/100

wat should i do then?

 

[Drakkith]

We have figured out that it takes 0.02285 seconds for a bullet to travel 30 feet. Thats 22.85 milliseconds. 50-100 ms is the response time for a human to even recognize something is happening, such as in a reflex. If the bullet takes 23 ms to travel, and a human takes 50-100 ms to even begin to react, what does that tell you?

 

[zmalik595]

Its impossible to react

 

[zmalik595]

to make sure, is the conclusion correct, it is impossible to react because the muman reaction is 50/100 m/s while the bullet speed is 23 millisecons?