When Tom and John are fighting and hitting each other in the car while their father is driving, it becomes unsafe behavior due to the following reasons:
1. **Distraction**: Their fighting can distract their father, who is driving the car, leading to a loss of focus on the road and potentially causing an accident.
2. **Lack of Control**: If their fighting escalates, their father may need to intervene, taking his hands off the steering wheel, which can result in a loss of control over the vehicle.
3. **Physical Harm**: Hitting each other can result in physical injuries not only to themselves but also to their father if they accidentally hit him while he is driving.
4. **Emotional Distress**: Their fighting can create a tense and stressful environment in the car, affecting the concentration and emotional state of their father, compromising the safety of everyone in the vehicle.
In conclusion, engaging in such behavior while in a moving vehicle poses risks to everyone's safety and can lead to serious consequences. It's important to maintain peace and order in the car to ensure a safe journey for all passengers.
