Question

A music teacher asked her students to set a really hard goal, such as increasing their practice time by 10 hours per week, which would cause her students to reach beyond what they think is possible. this is known as a(n)

Answer 1

The answer is Stretch Goal.  It is also called a Stretch Target, it is a high and difficult level of success that a student must achieve if they are to be considered to be doing their job in a satisfactory way.  Practicing 10 hours a week would cause the students to reach beyond what they think is possible.