As an airplane lands, it uses flaps to slow down. What kind of friction is this technology using?

Aregular polygon has angkes of size 150° each.how many side has the polygon

Awave is produced in a rope. the wave has a speed of 33 m/s and a frequency of 22 hz.

If two students are running down the hall toward each other, trying to get to class, and they have the same mass and acceleration, what will happen when they collide? will their forces cancel out or will each one experience a reaction?