A fountain with a depth of 5 feet is drained and then refilled. The water level (in feet) after t minutes can be modelled by f(t)=1/4abs{t-20}. A second fountain with the same depth is drained and filled twice as quickly as the first fountain. Describe how to transform the graph of f to model the water level in the second fountain after t minutes.
Then find the depth of each fountain after 4 minutes.
Justify your answer