Final answer:
Motorcyclists may make sudden changes due to the physics of gyroscopic precession, the Doppler effect, and angular momentum. Carefully pulling the handlebar creates a counter-intuitive turn due to the gyroscopic effect, and fast motion changes sound pitch because of the Doppler effect. Angular acceleration of the wheels aids maneuvering but requires cautious handling.
Step-by-step explanation:
You should expect a motorcyclist that you are following to make sudden changes because of various physics principles at play. When a motorcyclist is driving at highway speeds, they have to account for different physical effects such as gyroscopic precession, the Doppler effect, and angular momentum. For instance, when a physics student, driving his motorcycle, lightly pulls back on the right handlebar, the motorcycle tips to the left and brings about a left turn. This counter-intuitive action is due to the gyroscopic effect, where the force applied to the wheel causes a precession, and the bike turns in the opposite direction to the force applied. It is essential to be cautious when following motorcyclists because they might have to react spontaneously to maintain stability or avoid obstacles, which could include sudden changes in direction.
The Doppler effect also plays a role in how we perceive motorcycles on the road. The high-pitched scream of a motorcycle changes to a lower-pitch roar as it passes by a stationary observer. This shift in the frequency of sound waves is due to the relative motion between the source of the sound and the observer - the faster the motorcycle moves, the greater this shift in pitch. While this effect doesn't directly cause motorcyclists to make sudden changes, it's a related physical phenomenon that helps explain the dynamic nature of motorcycling.
The linear acceleration of a motorcycle is also accompanied by an angular acceleration of its wheels which contributes to its ability to maneuver quickly. The gyroscope-like behavior of the wheels while the motorcycle is in motion helps maintain balance but requires careful handling at high speeds.