Forces in Equilibrium
are in equilibrium, the resultant force
According to Newton's Second Law, a force
on an object can be equated to the product of its mass,
m, and acceleration,
a. Hence, if the mass
of the object, m, is not destroyed, the acceleration
of the object, a, must therefore be equal to zero. The object is
either stationary or moving at a constant velocity.
quantities, they can be represented with the use of
arrows. When three forces
are in equilibrium, they follow the triangle of forces rule
which states that the three arrows can form (make) a closed
triangle. The direction of the arrows follow one another, as shown
in the diagram below. The triangle of forces rule, for instance, can
be used to solve many textbook questions, including the ones
involving the weight(s)
required in a pulley system which is in equilibrium.
Besides the triangle of forces rule, questions involving forces
in equilibrium can also be solved using parallelograms and/or trigonometry.