Question

reading check

1. identify which of the four fundamental forces causes friction?

looking closer

1. infer if there was no friction between the match and the surface, would the match light? explain your answer.

reading check

1. list what are the two main types of kinetic friction?

Explanation:

• Question 8: Friction is caused by the electromagnetic force. At the microscopic level, the atoms and molecules of two surfaces interact via electromagnetic forces (such as the electrostatic forces between charged particles in the atoms). These interactions lead to the resistance we experience as friction.
• Question 9: A match lights due to the heat generated from friction. When you strike a match, the friction between the match head and the striking surface causes a rapid increase in temperature. This temperature increase is sufficient to ignite the chemicals (such as phosphorus - based compounds) in the match head. If there was no friction, there would be no heat generated from the relative motion between the match and the surface. So, the match would not light because the necessary ignition temperature for the match - head chemicals would not be reached.
• Question 10: The two main types of kinetic friction are sliding kinetic friction and rolling kinetic friction. Sliding kinetic friction occurs when one object slides over another (e.g., a block sliding on a table). Rolling kinetic friction occurs when an object rolls over a surface (e.g., a ball rolling on the ground).

Answer:

• 8. The electromagnetic force causes friction.
• 9. No, the match would not light. Friction generates heat which is needed to ignite the match - head chemicals. Without friction, there is no heat from the relative motion, so the ignition temperature is not reached.
• 10. The two main types of kinetic friction are sliding kinetic friction and rolling kinetic friction.