I understand Physical % Complete with respect to Earned value. If I create a task with one resource that has work of 40 hours it will be scheduled for a week. If I enter completed work of 20 hours , and the Physical Progress is 25%, Earned Value will project the final cost for the resource based on 80 hours to complete the task. The % Complete will be 50% however.

What I don't see happening, is Project extending the task duration to two weeks, for the 80 hour work projection. Does Project do this, or do you have to manually increase the task work to 80 hours to get it to extend the duration?