Activity 1: Demonstration activity (10 minutes)
Teacher will divide the students into each group (4-5 students per
group)
The teacher gives each group 1 thin flat sheet of paper, asking:
Put the flat paper under your mouth, if we blow hard on the top surface
of the paper, do you have any prediction about the paper, the paper will
hang down or be pushed up?
After making prediction, the groups made the request to blow the paper
of the teacher and commented on the phenomenon that happened.
Teacher commented and explained the phenomenon: Because when we blow
the paper, the air flow on the top side of the paper moves quickly,
causing the pressure on the surface of the paper to decrease, besides
the airflow below the paper. Standing still or moving slowly, the
pressure is greater than the top, causing the other end of the paper
to push up.
\(F=\ p.S\) (N)
In which: F is the lift force of the aircraft’s wing (N)
\(p\) is the difference in pressure between the bottom and top surface
of the wing (N /\(m^{2})\).
S is the total cross section of the wing ( \({(m}^{2})\)