Final answer:
The drag force on a moving object depends on its shape, size, velocity, and the fluid's density. For larger objects at higher velocities, the drag force is proportional to the square of the speed. For smaller objects or slower movement in a dense medium, it follows Stokes' Law with a linear relationship to velocity.
Step-by-step explanation:
The drag force on a moving object depends on several factors, including the object's shape, size, velocity, and the density of the fluid it is moving through. For larger objects such as bicycles, cars, and baseballs moving at a higher velocity through air, the drag force can be expressed using the formula FD = ½ CpAρv², where FD is the drag force, Cp is the drag coefficient, A is the cross-sectional area, ρ is the fluid density, and v is the velocity of the object.
For small objects or those moving at low speeds through a denser medium than air, the drag force follows a linear relationship with velocity as per Stokes' Law, which can be expressed as Fs = 6πηrν, where η is the fluid's viscosity, r is the radius of the object, and ν is the velocity.