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A Bullet Hits Steel Plate on TI-89 | Every Step Physics

October 20, 2013 · by physics · Bullets, Physics Videos

 

Bullet Hits Steel Plate on TI-89: Raw Transcript

This is a video from every step physics dot com
demonstrating how my program work on the TI-89 Titanium calculator
and other calculators in the TI system for physics and calculus problems
here’s a problem that is on many tests in physics
and ah if a bullet traveling at three hunderd fifty
meters per second strikes a steel plate
at an angle of 30 degrees as shown It recochets off
with the same angle at a speed of three hundred twenty meters
per second what is the magnitude of the impulse that
the plate gives the bullet
and in my programs ah you
find first what the problem is asking in this case it’s asking impulse
and you go to my menu and you scroll down for impulse
and then you on the side of your problem
instead of looking at it or thinking about the problem at all you just
put what’s given here which is mass
twenty grams and initial velocity
which is three hundred fifty meters per second final velocity would be
three hundred twenty meters per second and then a thirty degree angle
and here’s the picture of what’s happening and this is really vector addition
so let’s get started here ah you have to press second alpha
to put these letters in here to get to my program menu
p h y s i c s and then you have to press alpha again
to put the open and closed parenthesis and press enter and you are into my menu
I’ve scrolled down to impulse here to save some time
but you start it brings you to the top of the menu
and then you have all these other choices and uhm
we get to impulse we press enter
gives you these variables here for impulse
and right now in this problem we want the mass
the initial velocity the final velocity
and the angle we choose that
we enter your variables you have to press alpha first
before we enter any variables into the entry lines of my programs
so were going to press alpha and put down
put in twenty it also might give you kilograms or grams
in this case it gives you the bullet as grams so I’m going to put that there
it shows you you take twent and divide it by a thousand
to get point zero two kilograms which is necessary for the formula
and the initial velocity your going to press alpha
and put in three fifty that’s the way the bullet is traveling
and it’s not in centimeters it’s in meters
so were going to choose number two you can press or scroll to that choice
final velocity alpha three twenty
meters again per second and then the angle is
alpha thirty I always show you what you’ve entered
so you can change it this looks good to me
it’s been changed from grams to kilograms etcetera
and this is vector addition who would have known that
if you just saw a problem in a test ah here’s the impulse vector resultant
ah the square root of the x axis and y axis
and the I of the impulse and here’s the formula
and then we add the the all the variables
you write this on paper you don’t think about it
and the I y is six point seven newtons second
and the answer is six point seven two three one
newtons second pretty neat huh
EveryStepPhysics.com go to my site
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