- #1

rayjbryant

- 23

- 6

The magnet being used

terminal velocity ends up being: 1E-4 m/s

The main body code.:

```
% magnet dimensions [m]
d = .0127;
r = .00238;
%mass of magnet [kg]
m_w = .0017;
% other constants
u_0 = 1.26E-6; % permeability of free space constant T m/A
g = 9.81; % gravitational constant in/s^2
%coil properties [22 gauge wire] [m]
a = .00635; %radius
w = .000635; %width of wire
N = 100; % number of turns
c = pi*a*2; %circumference
wl = c*N; %wire length
cs = pi*(w/2)^2; %cross sectional area
rho = 1.7e-8; % resistivity of copper [ohm/m]
wr = (rho*wl)/cs; % resistance in wire [ohm]
lt = 0.3048; % length of tube
%magnetic properties
sm = 72730000; % magnetic surface charge density [Mx/m^2]
qm = pi*sm*r^2; %
eff_dist = .003175;
%terminal velocity
p = qm*d;
x = d/a;
val = scalingfunction(x);
v = (8*pi*m_w*g*rho*a^2)/(u_0^2*qm^2*w*val);
```

The scaling function code.:

```
function [val] = scalingfunction(x)
fun = @(x,y) ((1./(y.^2+1).^(3/2))-(1./((y+x).^2 + 1)).^(3/2)).^2;
val = integral(@(y) fun(x,y),-Inf,Inf);
end
```

terminal velocity ends up being: 1E-4 m/s