- Ground is a kind of object
- A wagon is a kind of object
- Hence, a wagon and ground are kinds of objects

- A wagon and ground are kinds of objects
- When the wagon is moving down the hill, it is moving against the ground
- Friction occurs when two object 's surfaces move against each other
- So, friction occurs between the wagon and the ground

- Friction occurs between the wagon and the ground
- A wagon is a kind of object
- Friction causes the speed of an object to decrease
- Therefore, friction causes the speed of the wagon to decrease

- Friction causes the speed of the wagon to decrease
- If the speed of an object keeps decreasing, the object will come to stop
- A wagon is a kind of object
- Therefore, friction causes the wagon to stop

Therefore, friction causes the wagon to stop
[Question]A child rides a wagon down a hill. Eventually, the wagon comes to a stop. Which is most responsible for causing the wagon to stop?
[Context]- Ground is a kind of object 
- If the speed of an object keeps decreasing, the object will come to stop 
- A wagon is a kind of object 
- Friction causes the speed of an object to decrease 
- When the wagon is moving down the hill, it is moving against the ground 
- Friction occurs when two object 's surfaces move against each other