I tried to solve projectile motion problem (velocity about physic) with matlab . I have some troubles ... Please help me immediately

g=9.80665;

T=37;

V0=100;

Vx=(V0*cos(T))

Vy=abs(V0*sin(T))

tu=(Vy/g)

t=(1:tu) --------------- When I changed like that t=(1:0.1:tu) / float

Programme gives error like that:

Array indices must be positive integers or logical values.

Error in V_T (line 9)

y(t)=(Vy-g*(t))

y(t)=(Vy-g*(t)

x(t)=Vx

y2(t)=(-Vy-g*(t))

A=[y(t),y2(t)]

B=[x(t),x(t)]

V=A.^2+B.^2

[William Rose]

@Sevval Zengin,

y=Vy-g*t; %should work

If T is in degrees (which it appears to be), then you should use

Vx=V0*cosd(T);
Vy=V0*sind(T);

Also, x(t)=... and y2(t)=... will produce errors, and you shoudl use x=... and y2=...

Check the right hand side of your equations. Are they correct?

Answer 1

[David Hill]

Help immediately? Lucky to get a response.

g=9.80665;
T=37;
V0=100;
Vx=V0*cosd(T);
Vy=V0*sind(T);
tu=Vy/g;
t=0:.001:tu;
Vy=Vy-g*t;
Vx=Vx*ones(size(t));
V=hypot(Vx,Vy);
plot(t,Vx,t,Vy,t,V);

[Sevval Zengin]

why did you write cosd(T) instead of cos(T) ?

[Sevval Zengin]

By the way thank you sooo much.

[Sevval Zengin]

ıt s right :)

Answer 2

[William Rose]

@Sevval Zengin,

I agree with the comment of @David Hill.

I inteneded to make an answer not a comment.

y=Vy-g*t; %should work

If T is in degrees (which it appears to be), then you should use

Vx=V0*cosd(T);
Vy=V0*sind(T);

Also, x(t)=... and y2(t)=... will produce errors, and you shoudl use x=... and y2=...

Check the right hand side of your equations. Are they correct?

[Sevval Zengin]

thank you so much :)