Question

State the condition when a body is in (a) static (b) dynamic, equilibrium. Give one example each of static and dynamic equilibrium.

Answer 1

(a) When a body remains in the state of rest under the influence of the applied forces, the body is in static equilibrium. For example, a book lying on a table is in static equilibrium.
(b) When a body remains in the same state of motion (translational or rotational), under the influence of the applied forces, the body is said to be in dynamic equilibrium. For example, a rain drop reaches the earth with a constant velocity is in dynamic equilibrium.