Final Answer:
While Newton's first law suggests that an object in motion stays in motion, the real-world scenario of a bicycle requires continuous pedaling due to the presence of friction and air resistance.
Step-by-step explanation:
Newton's first law of motion states that an object at rest will remain at rest, and an object in motion will remain in motion unless acted upon by an external force. In the case of a bicycle, once set in motion, it tends to keep moving forward.
However, Newton's first law assumes an idealized scenario with no external forces. In reality, various forces like friction and air resistance act on a moving bicycle, gradually slowing it down.
Friction between the bicycle's tires and the surface it travels on is a significant factor. As the tires roll, friction between the tire and the road surface acts as a resistive force, gradually decreasing the bicycle's speed.
Additionally, air resistance, especially at higher speeds, creates a force opposing the direction of motion. These forces contribute to the need for continuous pedaling to compensate for the energy lost to friction and air resistance.
Therefore, while Newton's first law provides a fundamental understanding of motion, real-world factors necessitate continuous pedaling to counteract the opposing forces and maintain a constant speed.
This illustrates the importance of considering external forces and practical conditions when applying physical principles to everyday situations.