Question

2. Suppose one of your classmates says “The net force on an airplane is zero, therefore

must be on the ground and at rest." Is this a correct statement! Why or why not?

Answer 1

This is a false statement. Newton's first law says that if the net force on an object is zero, the object stays in UNIFORM MOTION. That means it keeps moving at a constant speed, in a straight line. It can certainly have some speed, in some direction, but without any net force, they CAN'T CHANGE.