This little girl is at equilibrium on her trampoline.
Equilibrium is defined by"The state of a body or physical system
that is at rest or in constant and unchanging motion. A system
that is in equilibrium shows no tendency to alter over time. If
a system is in static equilibrium
there are no net forces and no net torque in the system. If a
system is in stable equilibrium
small disturbances to the system cause only a temporary change
before it returns to its original state".
These four kids on the
trampoline are not at equilibrium. The trampoline might be
trying to get there but it will have a hard time until all of
the kids lay down and are st rest. They probably will be after
jumpimg around so much.