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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

buy my programs and pass physics