1. Gravitational Force (Weight): The force of gravity pulls the duck downwards towards the Earth. This force is counteracted by the upward force exerted by the surface on which the duck is standing or resting.
2. Normal Force: The normal force is an upward force exerted by the supporting surface on the duck's feet. This force opposes the gravitational force and prevents the duck from sinking into the surface. The normal force is perpendicular to the surface and equal in magnitude to the weight of the duck.
3. Friction: Friction is the force that resists the relative motion of two surfaces in contact. When the duck is stationary on a surface, the friction between its feet and the surface prevents it from slipping or sliding.
4. Muscle Forces: The duck's muscles also play a role in maintaining its stationary position. The duck can adjust the tension and contraction of its muscles to stabilize its body and keep its balance.
5. Buoyancy (if in water): If the duck is floating on water, the buoyant force exerted by the water upwards counteracts the gravitational force, allowing the duck to stay afloat.
It's important to note that these forces work in concert to maintain the duck's stationary state. Any imbalance or changes in these forces, such as a sudden movement or a change in the supporting surface, can cause the duck to start moving.