A 2 kg object is initially at rest. A net external force acts on the object over a period of 5 seconds. The force as a function of time behaves as follows: it increases linearly from 0 N at 0 s to 10 N at 2 s; then remains at 10 N from 2 s to 4 s; then decreases linearly back to 0 N from 4 s to 5 s. What is the final velocity of the object after 5 seconds?