Which of the following statement is an example of contact force?
I. Electrostatic force
II. Friction
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2: Only II.
Explanation:
Forces are primarily classified into two categories:
Contact Forces and Non-contact Forces. Let us analyze the given statements:
1. Statement I (Electrostatic Force): This is a non-contact force. This force acts when two charged objects are not in contact with each other. For example, when a comb is rubbed against hair and brought near small pieces of paper, the paper pieces are attracted to it without being touched.
2. Statement II (Friction): This is an example of a contact force. Frictional force always acts between the surfaces of two objects when they are in contact with each other and are moving (or attempting to move) relative to one another.
Additional Facts:
• Muscular Force: This is also a contact force because our muscles physically touch an object in order to push or lift it.
• Magnetic Force: This is a non-contact force because a magnet can attract iron objects from a distance without touching them.
Potential Questions for Upcoming Exams:
Question: Which of the following is a non-contact force? (Options: Friction, Muscular Force, Magnetic Force, Tension Force)
Answer: Magnetic Force.
Question: When you stop pedaling while riding a bicycle, the bicycle eventually comes to a halt; which force is responsible for this?
Answer: Frictional Force (between the tires and the road).
Question: The Earth pulls an object towards itself; what type of force is this?
Answer: Gravitational Force (a non-contact force).