👟Helpful: gripShoe treads stop you slipping.

🚲Helpful: brakesFriction slows wheels down.

✍️Helpful: writingPencils need friction to leave marks.

⚙️Problem: wearMoving parts wear out; oil reduces friction.

🔥Problem: heatRubbing makes heat (warm hands!).

🚀Problem: dragStreamlined shapes cut air resistance.