Lesson 3: Friction: The Slowing-Down Force
When two surfaces rub against each other, they create a force called friction. Friction slows things down.
On a golf course, friction is everywhere. When a golf ball rolls across the fairway, the grass creates friction that gradually slows the ball to a stop. When a ball rolls on a fast green, there is less friction — so it rolls farther and faster.
The rough has more friction than the fairway because the longer grass grabs the ball more. That is part of why it is harder to control a shot from the rough — the friction changes the ball’s speed and direction.
Friction is also why golf shoes have cleats — the cleats dig into the ground and create friction between your feet and the turf, keeping you from slipping during your swing.
Friction = the force created when two surfaces rub together. It always works against motion — it slows things down.
More friction = the ball slows down faster. Less friction = the ball rolls farther and faster.
Why do you think the putting green is mowed so short? What happens to friction when the grass is very short? What happens when it is very long?
Roll a golf ball across three different surfaces: smooth floor, carpet, and grass. Roll it with the same force each time. Measure or estimate how far it travels on each surface before stopping. Draw a bar chart showing the distance on each surface. Which surface has the most friction? Which has the least? How does this connect to how golf courses are designed?
If you don’t have access to grass indoors, a towel works well as a high-friction surface. The bar chart asks your child to represent data visually — a scientific skill. Even rough estimates and hand-drawn bars are valuable. The habit of turning observations into data is what matters.