Answer:
we agree with
Edgar: The net force on the ball at the top position is 9 N. Both the tension and the weight are acting downward so you have to add them.
Explanation:
Weight of the ball is given as

so we have


now tension force at the top is given as


Now at the top position by force equation we can say that ball will have two downwards forces
1) Tension force
2) Weight of the ball
so net force on the ball is given as


So we agree with
Edgar: The net force on the ball at the top position is 9 N. Both the tension and the weight are acting downward so you have to add them.
The correct answer is b i believe
The first two are always the reactants the products come after so they are last
The angle of refraction would be further less