In this part of the question, we've got the
same lorry as before, with the same forces
acting on it. We want to find the distance
from the front wheel to the centre of mass,
d. Call the distance between the front wheel
and the rear wheel L. The lorry is in equilibrium,
which means the resultant moment acting on
it must be zero about any point. And if we
take moments about the centre of mass of the
lorry, we find that the moments clockwise
are m1gd and the moments anticlockwise are
m2g(L-d), and these must be equal because
the lorry is in equilibrium. We don't need
to worry about the lorry's weight because
it acts from the centre of mass, and that's
the point at which we're taking the moments.
Now all we need to do is rearrange this and
we can find d in terms of things we know.
