A passenger in a car moving round a curved road is thrown towards the outside of the curve. What force throws him in this direction ?

Answer

To solve the question, we need to analyze the situation of a passenger in a car moving around a curved road and understand the forces at play.

### Step-by-Step Solution:

1. **Understanding Circular Motion**: When a car moves along a curved path, it is undergoing circular motion. The car needs to exert a force towards the center of the curve to keep moving in that circular path.

2. **Centripetal Force**: The force that keeps the car (and the passenger) moving in a circular path is called the centripetal force. This force acts towards the center of the circular path.

3. **Inertia of the Passenger**: According to Newton's first law of motion, an object in motion will remain in motion unless acted upon by an external force. The passenger, due to inertia, tends to continue in a straight line. When the car turns, the passenger feels as if they are being thrown outward.

4. **Centrifugal Effect**: From the passenger's frame of reference (inside the car), it appears that there is a force pushing them outward. This is often referred to as centrifugal force. However, it is not a real force acting on the passenger; rather, it is the effect of inertia.

5. **Conclusion**: The passenger feels as if they are being thrown outward due to their inertia, which causes them to resist the change in direction. The actual force acting on the passenger is the centripetal force exerted by the car, which keeps them in circular motion.

### Final Answer:
The force that appears to throw the passenger towards the outside of the curve is the effect of inertia, often referred to as centrifugal force in a non-inertial reference frame. The real force acting on the passenger is the centripetal force directed towards the center of the curve.

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