as the friction increases, the resistance on the object to move will increase & as roughness of a surface increases , friction will increase ->  as the roughness of a surface increases, the resistance on the object to move will increase  as the roughness of a surface increases, the resistance on the object to move will increase & wood has a smooth surface & carpet has a rough surface ->  the resistance on the object to move on the carpet will be larger than on the wood  the resistance on the object to move on the carpet will be larger than on the wood & a toy car is a kind of object ->  the resistance on the toy car object to move on the carpet is larger than on the wood  the resistance on the toy car object to move on the carpet is larger than on the wood & as the resistance on the object to move increase, the object will move slower -> the toy car will move slower on the carpet than on the wood