Consider a vehicle going on a horizontal road towards east. Neglect any force by the air. The frictional forces on the vehicle by the road

Options

A. is towards east if the vehicle is accelerationg
B. is zero if the vehicle is moving with a uniform velocvity
C. must be towards east
D. must be towards west

Answer

To solve the problem of determining the direction of the frictional forces acting on a vehicle moving on a horizontal road towards the east, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Direction of Motion**:
- The vehicle is moving towards the east. This means that the velocity vector of the vehicle is directed to the east.

2. **Understand the Wheel's Movement**:
- For the vehicle to move forward (east), the wheels must rotate in a clockwise direction. This clockwise rotation means that the bottom part of the wheel is moving backward (to the west) as it contacts the road.

3. **Determine the Reaction Force**:
- According to Newton's Third Law of Motion, for every action, there is an equal and opposite reaction. The wheels of the vehicle push against the road in the backward direction (west), which creates a reaction force from the road.

4. **Identify the Frictional Force**:
- The frictional force acts in the opposite direction to the motion of the wheel at the point of contact. Since the wheels are pushing backward (to the west), the frictional force exerted by the road on the wheels will act forward (to the east) to propel the vehicle.

5. **Consider Different Scenarios**:
- If the vehicle is accelerating, the frictional force will be directed towards the east to increase the vehicle's speed.
- If the vehicle is moving with a uniform velocity (constant speed), the net force acting on the vehicle is zero. In this case, the frictional force balances any opposing forces, and it can be considered as zero if no other forces are acting on the vehicle.

### Conclusion:
- The frictional force on the vehicle by the road is directed towards the east when the vehicle is accelerating. If the vehicle is moving at a constant velocity, the net frictional force can be considered as zero.

### Final Answer:
- The frictional force acting on the vehicle by the road is towards the east when the vehicle is accelerating. If the vehicle is moving with uniform velocity, the frictional force can be considered as zero.

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