Using for loop for midpoint method

Hi guys, this is my code

m = 1000;

f = 75000;

v0 = 0;

h = 0.1;

tspan = [0 10];

c = [50,100,500,1000,2000];

dvdt = cell(1,length(c));

for i = 1:length(c);

dvdt{i} = @(t,v) (f-c{i}*v)/m;

end

t =cell(1,length(c));

v =cell(1,length(c));

for k = 1:length(c)

[t{k},v{k}]=midpoint(dvdt{1,k},tspan,v0,h)

end

%% Question

I want to use midpoint to calculate the t and v, and my dvdt is relied on c(constant values run from 50 to 2000). The code works, but t and v are released just only based on c = 50, which means my for loop does not work. Can someone please help !!!

Thanks in advance