Q1: What force is responsible for allowing us to walk without slipping?
Answer: Friction
Explanation: Friction between our feet and the ground provides grip, making walking possible.
Q2: What force helps a pencil leave marks on paper while writing?
Answer: Friction
Explanation: Friction between the pencil and paper allows graphite to be deposited, forming writing.
Q3: What unwanted effect does friction produce in moving machines?
Answer: Heat
Explanation: Friction between machine parts generates heat, causing energy loss and wear.
Q4: What is worn out in machines due to continuous friction?
Answer: Parts
Explanation: Friction causes gradual wearing of machine parts, reducing their efficiency.
Q5: What is used to reduce friction in the moving parts of a bicycle chain?
Answer: Oil
Explanation: Lubricants like oil reduce direct contact between parts, lowering friction.
Q6: What type of soles are used in shoes to increase friction while walking?
Answer: Grooved
Explanation: Grooved soles increase surface irregularities, enhancing grip through friction.
Q7: What device uses friction to slow down or stop a vehicle?
Answer: Brake
Explanation: Brakes create friction with the wheels, converting motion into heat to stop the vehicle.
Q8: What is friction considered due to both its helpful and harmful effects?
Answer: Evil
Explanation: Friction is called a necessary evil because it helps in motion control but also causes wear.
Q9: What is used between wooden blocks to reduce friction in old transport methods?
Answer: Rollers
Explanation: Rollers reduce sliding friction by converting it into rolling friction, which is less.
Q10: What do we call the unwanted resistance that reduces efficiency in machines?
Answer: Friction
Explanation: Friction resists motion and causes energy loss, reducing the overall efficiency of machines
