Index exceeds matrix dimensions error message

I'm trying to use a while loop to create vectors so that I can plot the values but I keep getting the "Index exceeds matrix dimensions" error message. Any help is appreciated. This is my code:

figure(1)

z1=.6;

z2=.85;

z3=1.23;

V=sqrt(2*9.81*(z3-z1));

i=1;

t=0;

%%

while z3(i) >=0

x(i)=t*V;

Z3(i)=z3-.5*9.81*(t^2);

t=t+.25;

i=i+1;

end

Answer 1

[KALYAN ACHARJYA]

Yoi defined z3 as scalar, but in the while loop you trying acess it as vectors

#Defined here

z3=1.23;

#

while z3(i)>=0
    %...
end

Here waht does z3(i) means. In Matlab z3(i)

%.................................................................^ means array indexing

See the following example

>> Z3=4;
>> Z3(1)
ans =
     4
>> Z3(2)
Index exceeds matrix dimensions.
>> 

When "i" incremented within while loop, in the next iteration, how does z3 gets the value when i is greater than "i", like z3(2),z4(3)..so on.

Hope it helps, any issue let me know.

[Baxter Hughes]

z3, z2, and z1 are all heights of 3 different jets of water and the while loops purpose is to determine the path of the jet over time. I used that expression for my while loop because i wanted the loop to run until Z3 got to zero.

[KALYAN ACHARJYA]

You have to figure out, it seems simple

z1=.6;
z2=.85;
z3=1.23;
V=sqrt(2*9.81*(z3-z1));
i=1;
t=0;
while z3>=0
    x(i)=t*V;
    z3=z3-0.5*9.81*(t^2);
    t=t+.25;
    i=i+1;
end

Do the proper notbook calculation and show me, so that I can help you Matlab implementation.