Fix ex09 and commit PDF
Empty document for ex10
Calculations for sheet 10, still needs comments

Sage session, for reference:

    sage: class Mass:
    ...       def __init__(self, x, y, z, m):
    ...           self.x = x
    ...           self.y = y
    ...           self.z = z
    ...           self.m = m
    ...
    sage: def inertia_tensor(masses):
    ...       I = matrix(3)
    ...       for m in masses:
    ...           I += m.m * matrix([[m.y^2+m.z^2, -m.x*m.y, -m.x*m.z], [-m.y*m.x, m.x^2+m.z^2, -m.y*m.z], [-m.z*m.x, -m.z*m.y, m.x^2+m.y^2]])
    ...       return I
    ...
    sage: body_masses = [
    sage: Mass(0, 0, 0, 8),
    sage: Mass(0, 0.4, 0, 10),
    sage: Mass(0, 0.8, 0, 12),
    sage: Mass(0, 1.2, 0, 14),
    sage: Mass(0, 1.6, 0, 6),
    sage: ]
    sage: arms_up_masses = [
    sage: Mass(-0.8, 1.2, 0, 2),
    sage: Mass(-0.4, 1.2, 0, 3),
    sage: Mass(0.4, 1.2, 0, 3),
    sage: Mass(0.8, 1.2, 0, 2),
    sage: ]
    sage: arms_down_masses = [
    sage: Mass(-0.24, 0.48, 0, 2),
    sage: Mass(-0.24, 0.88, 0, 3),
    sage: Mass(0.24, 1.52, 0, 3),
    sage: Mass(0.24, 1.92, 0, 2),
    sage: ]
    sage: I = inertia_tensor(body_masses+arms_up_masses)
    sage: I
    [ 59.2000000000000 0.000000000000000 0.000000000000000]
    [0.000000000000000  3.52000000000000 0.000000000000000]
    [0.000000000000000 0.000000000000000  62.7200000000000]
    sage: omega = vector([0,1,0])
    sage: L = I*omega
    sage: L
    (0.000000000000000, 3.52000000000000, 0.000000000000000)
    sage: I_prime = inertia_tensor(body_masses+arms_down_masses)
    sage: I_prime
    [ 61.8880000000000 -1.15200000000000 0.000000000000000]
    [-1.15200000000000 0.576000000000000 0.000000000000000]
    [0.000000000000000 0.000000000000000  62.4640000000000]
    sage: omega_prime = I_prime \ L
    sage: omega_prime
    (0.118152524167562, 6.34741615944624, 0.000000000000000)
Fixed column vectors, begun 10.5