Skip to main content

FREE FALL


## A function, free fall, that takes in h (in metres), and
## returns the final velocity of the ball at the
## time step just before it touches the ground and makes
## a plot of velocity versus time.
function freefall(h)
## constants and initializations
v=0; ## initial velocity(at rest) [m/sec]
y=h; ## initial altitude of the ball from the ground [m]
t=0; ## initial time[sec ]
B1=0.05; ## Coeff of the term prop to v [kg/sec]
B2=6E-4; ## Coeff of the term prop to v^2 [kg/m]
m=0.25; ## Mass of the ball [kg]
g=9.8; ## Gravitational acceleration [m/sec^2]
dt=0.1; ## Time increment [sec]
n=1; ## Initialize the loop index[dimensionless]
## Run the loop or iterate until the vertical component is
## smaller than zero.
while (y(n)>0);
## decrease the altitude in each step
y=[y;y(n)+v(n)*dt]; ## and accumlate the results in the array
## of the vertical displacement.
## increase the time in each step
t=[t;t(n)+dt]; ## and accumlate the results in the array
## of the time for the time axis in the plot.
## increase the vertical velocity
v=[v;v(n)-dt*(g-B1*v(n)/m+B2*v(n)^2/m)]; ## in each step and
## accumlate the results
## in the array of vertical velocity.
n++; ## increase n by 1 in each step
endwhile
vfinal=-v(n) ## magnitude of the final velocity of the ball at the
## time step just before it touches the ground
plot(t,-v,';drag;') ## plot of the magnitude of the velocity versus time.
endfunction

Comments

Popular posts from this blog

SIMPLE AND MODIFIED EULER METHOD

##Usage:Call Octave from terminal ##and then call EulerMethodUmitAlkus.m ##from octave and finally ##press enter. That's all. ##Simple Euler Method ##Constants and initializations x=[]; ## initial empty vector for x y=[]; ## initial empty vector for y x(1)=1; ## initial value of x y(1)=1; ## initial value of y h=1E-3; ## increment in x dery=[]; ## 1st derivative of y wrt x dery(1)=0;## 1st entry of dery n=1; ## inital loop index for while ## enter the while loop for the interval x=[1,2] while (x(n)<=2) x(n+1)=x(n)+h; dery(n+1)=x(n)*x(n)-2*y(n)/x(n); ##given y(n+1)=y(n)+h*dery(n+1); ##Euler method n++; endwhile ##exit from the 1st while loop ##Modified Euler Method ##Constant and initializations x(1)=1; ## beginnig of the interval [1,2] ymod(1)=1; ## inital value for modified y. ymid=[]; ## empty vector function evaluated at x midpoint xmid=[]; ## empty vector func. of midpoints of the interval h in x-axis. derymod=[]; ## modified derivatives of ymod

NEWTON-RAPSON METHOD-8th degree Legendre polynomial

## Newton-Rapson Method to the smallest non negative root ## of the 8th degree Legendre Polynomial ## P8(x)=(1/128)(6435x^8-12012x^6+6930x^4-1260x^2+35) ## where -1<=x<=1. ## for the smallest non negative root, we can ignore ## all the terms except the last two by truncated ## the function to be zero and find ## x=0.167 as the initial smallest non negative ## root. ##Constants and initializations x=[]; ## Empty array for the iterated x roots x(1)=0.16700000; ## Initial guess to begin the iteration for the ## smallest non-negative root. L8=[]; ## Empty array for the Legendre polynomial L8p=[]; ## Empty array for the derivative of the Legendre polynomial for i=1:100 ##The value of the function at x L8(i)=(1/128)*(6435*x(i)^8-12012*x(i)^6+6930*x(i)^4-1260*x(i)^2+35); ##The value of the derivative of the function at x L8p(i)=(1/128)*(6435*8*x(i)^7-12012*6*x(i)^5+6930*4*x(i)^3-1260*2*x(i)); x(i+1)=x(i)-L8(i)/L8p(i); ## the iteration endfor ## For plot let's