It’s fairly easy to demonstrate this if you have a friend with a bicycle. Have someone on a bike stay still and hold the brakes, and press firmly on their back.

It’s fairly easy to demonstrate this if you have a friend with a bicycle. Have someone on a bike stay still and hold the brakes, and press firmly on their back. It’s easy. Then have them bike at a slow jogging pace, run along with them, and try to apply the same force on their back. It will be hard work.