In the schoolyard there is a swing that hangs from the tree branch. The swing is 50cm from the ground and the tree grows at a rate of 5cm per year.
How high will the swing be in 10 years?
The trees increase in height as the canopy grows. A branch that leaves the trunk at a certain height of the base will always remain at the same height. Thus the swing will continue 50cm from the ground In 10 years.
You can find a more detailed explanation here.