Final answer:
Option 3. is correct. The minimum recommended following distance in ideal conditions is 3 seconds. This distance allows enough time to react and stop safely. Pedestrians should wait until a car is over 11 car lengths away before crossing if cars take 3 seconds to travel 50 meters.
Step-by-step explanation:
The minimum recommended following distance in ideal riding conditions is typically suggested to be 3 seconds. This following distance allows a driver enough time to perceive a hazard, react, and safely stop to avoid a collision. It is important to note that this distance can increase depending on various factors such as road conditions, weather, and the driver's reaction time.
In the scenario provided, where Bridget observes cars traveling from one pole to another, we can make a judgment on safely crossing a road by considering the following distance. If most cars take 3 seconds to travel 50 meters, then a pedestrian would want to wait until a car is at least 50 meters away before considering crossing to ensure that the car has enough time to stop if necessary. Assuming the average car length is about 4.5 meters, this distance would be a little over 11 car lengths.
Regarding stopping distances, they can vary greatly. For example, a car traveling at 30.0 m/s on a dry pavement will have a different braking distance than on wet pavement. It is pivotal to consider these variables, along with the driver's reaction time, when calculating safe stopping distances and deciding when it might be safe to cross a street.