Final answer:
The unbalanced force on the tennis ball is to the right, while the ball will move to the left when the string breaks. The unbalanced force on the tennis ball is to the left due to a larger leftward force (Fw) compared to the rightward force (Fc), and the tennis ball will move in a straight line tangent to the arc at the point where the string breaks.
Step-by-step explanation:
The direction of the unbalanced force on the tennis ball is to the right.
The unbalanced force, labeled as F, is shown as an arrow pointing to the right on the diagram.
The direction that the tennis ball will move when the string breaks is to the left.
This is indicated by the arrow labeled as D, which points to the left on the diagram.
The unbalanced force on the tennis ball is to the left due to a larger leftward force (Fw) compared to the rightward force (Fc), and the tennis ball will move in a straight line tangent to the arc at the point where the string breaks.
The question asks the student to analyze forces influencing a tennis ball's movement and to anticipate the tennis ball's trajectory upon the breaking of a string. We are dealing with two concepts: the direction of an unbalanced force and the trajectory of the tennis ball after the string breaks, which involves Newton's First Law of Motion.
a. According to Newton's Second Law, the unbalanced force on an object is the net force which causes it to accelerate. In the given diagram, the tennis ball is experiencing two horizontal forces, Fc to the right and Fw to the left. Since Fw (13.0 N) is larger than Fc (9.0 N), the unbalanced force on the tennis ball would be to the left. One would draw an arrow pointing left, labeled F.
b. When the string breaks, the tennis ball would follow a straight-line trajectory in the direction it was moving at that instant. This direction is tangent to the arc of the ball's motion at the point of release. An arrow should therefore be drawn from the point where the string breaks, in a direction that is tangential to the path of the tennis ball at that point, this arrow should be labeled D.