Trajectories

The Code:

clc;
clear;

% inialization
y0=10;
v0=15;
a=-9.81;

% time
t1=0:5;
t2=0:0.01:5;

% the equation
y1=y0+v0.*t1+0.5.*a.*t1.^2;
y2=y0+v0.*t2+0.5.*a.*t2.^2;

plot(t1,y1);
figure
plot(t2,y2);

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The resultant figure for a step increase of 1s

The resultant figure for a step increase of 0.01s