Can't figure out how to fix integer/logical error

I am writing a script to plot the trajectory of a ball. I can't quite figure out how to fix an error I have. I was thinking about using a loop, but I am not familiar enough with loops to know what to do.

Here is my script:

% Creates plot of ball based on height and velocity

% Gathers height and velocity from user
h = input('How high is the ball in meters? ');
v = input('What is the speed of the ball in m/s? ');

% Data for time
t = linspace(0,30,200);

% Calculates Height
h(t) = (.5)*(-9.81)*power(t,2)+(v*t)+h;

% Calculates Velocity 
v(t) = ((-9.81)*t)+v; 

% Plots Data
hold on
title ('Height and Velocity of a Ball')
xlabel ('Velocity (v) [m/s]')
ylabel ('Height (h) [m]')
plot (t,h(t),'r*')
plot (t,v(t),'bo')
legend ('Height', 'Velocity','location','northwest')

Here is the error I get

Subscript indices must either be real positive integers or logicals.

Error in HW5_Prob_1_2_3 (line 39)
h(t) = (.5)*(-9.81)*power(t,2)+(v*t)+h;

Answer 1

[Birdman]

% Creates plot of ball based on height and velocity
% Gathers height and velocity from user
h = input('How high is the ball in meters? ');
v = input('What is the speed of the ball in m/s? ');
% Data for time
t = linspace(0,30,200);
% Calculates Height
h = (.5).*(-9.81).*power(t,2)+(v.*t)+h;
% Calculates Velocity 
v = ((-9.81).*t)+v; 
% Plots Data
hold on
title ('Height and Velocity of a Ball')
xlabel ('Velocity (v) [m/s]')
ylabel ('Height (h) [m]')
plot (t,h,'r*')
plot (t,v,'bo')
legend ('Height', 'Velocity','location','northwest')

[Travis Schauer]

Thank you!

Answer 2

[Aletta Wilbrink]

The problem is t. h(t) asks for integers.

It does work if you do:

t = 1:30;