How to create matrix array using while loop and time increment?

34 views (last 30 days)
I have a problem where i want to solve a problem where an apple falls from a tree from 3m before hitting the ground. Assuming there is no air resistance, how long will it take to hit the ground? I have to create an array with time increments until the distance becomes 0 at the final time. So first column should show my time and second column will show the distance going down at every increment.
y0=2;
g=-9.81;
t = 0;
i=0;
y1=y0;
a = zeros([],2);
while y1>=0
i=i+1;
t=t+0.10;
y1=y0-0.5*g*t.^2;
a(i,:) = [t,y1]
end
disp(a)
0.0065 2.0726 %sample results
0.0065 2.0789
0.0065 2.0853
0.0065 2.0917
0.0065 2.0981
0.0066 2.1046
0.0066 2.1110
0.0066 2.1174
But when I run my code, it won't stop running and instead of 0.10 increments, the time looks off. How do I use the while loop (must use) to find the time it takes for the final y value to be 0.

Accepted Answer

DGM
DGM on 16 Feb 2022
Edited: DGM on 16 Feb 2022
Well, that's what happens when you drop an anti-gravity apple.
y0 = 2;
g = -9.81;
tstep = 0.01;
t = 0;
i = 0;
y1 = y0;
a = zeros([],2);
while y1 >= 0
i = i + 1;
t = t + tstep;
y1 = y0 + 0.5*g*t.^2;
a(i,:) = [t,y1];
end
plot(a(:,1),a(:,2))
  1 Comment
Kenny Gee
Kenny Gee on 16 Feb 2022
okay, i see where i made my mistake. sorry about the actual equation. I wanted to learn to do while loop. Thank you :)

Sign in to comment.

More Answers (1)

David Hill
David Hill on 16 Feb 2022
y1=y0+0.5*g*t.^2;%needs to be + (gravity is negative)

Categories

Find more on Loops and Conditional Statements in Help Center and File Exchange

Products


Release

R2021b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by