Final answer:
While walking, gravity, friction, and muscular force influence movement. A soccer ball being kicked, a dolphin jumping, and a parachutist drifting to Earth all experience forces such as applied force, gravity, and resistance from their respective environments.
Step-by-step explanation:
While walking from one end of the room to the other, forces including gravity, friction, and the person's muscular force contribute to movement. Gravity exerts a downward force that is counteracted by the normal force from the floor, preventing the person from sinking into the ground. Friction, which depends on the nature of the surface (like concrete or a rug), opposes the movement of the feet but also allows one to push against the ground to move forward. The force exerted by the muscles in the legs pushes the walker forward against the frictional force.
Examples of Forces Acting on Moving Objects
- A soccer ball being kicked is influenced by forces like the kicker's foot (applied force), gravity, air resistance (drag force), and friction from the ground.
- A dolphin jumping is affected by gravity, its muscular force, and water resistance.
- A parachutist drifting to Earth experiences the force of gravity and air resistance as well.
When analyzing movement, understanding the critical thinking components of force is essential. For example, if only two forces act on an object, one to the left and the other to the right, the object will move in the direction of the stronger force. Additionally, nonconservative forces like friction can perform work that depends on the path taken, as seen in moving an object across different surfaces with varying amounts of friction.