Contents
Dictionary
APPENDICES
1 Table of areas and volumes
2 Table of centres of mass
3 Table of moments of inertia
4 Table of derivatives
5 Table of integrals
6 Table of common ordinary differential equations and
solutions
7 Table of series
8 Table of convergence tests for series
9 Table of common inequalities
10 Table of trigonometric formulae
11 Table of symbols
12 Table of Greek letters
13 Table of Roman numerals
14 Table of Fields Medal Winners

centre of symmetry See SYMMETRICAL ABOUT A POINT.
centrifugal force See FICTITIOUS FORCE.
centripetal force Suppose that a particle P of mass m is
moving with constant speed v in a circular path, with centre at
the origin O and radius r0. Let P have polar coordinates
(r0,θ). (See CIRCULAR MOTION.) Then and the
acceleration of the particle is in the direction towards O and
has magnitude . It follows that, if P is acted on by a force
F, this force is in the direction towards O and has magnitude
mv2/r0. It is called the centripetal force.
For example, when an unpowered satellite orbits the Earth at
a constant speed, the centripetal force on the satellite is the
gravitational force between the satellite and the Earth.
centroid = CENTRE OF MASS. See also CENTROID (of a
triangle).
centroid (of a triangle) The geometrical definition of the
centroid G of a triangle ABC is as the point at which the
*medians of the triangle are concurrent. It is, in fact,
‘two-thirds of the way down each median’, so that, for
example, if A′ is the midpoint of BC, then AG = 2GA′. This is
indeed the point at which a triangular *lamina of uniform
density has its *centre of mass. It is also the centre of mass of
three particles of equal mass situated at the vertices of the

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