Question

True or False: Once the object hits the water, the forces are balanced and the object will stop. Support your answer with reasoning.

Answer 1

False. Once the box hit the water, the forces are balanced (50 N down and 50 N up).

Answer 2

Common sense, the object will not stop once it hits the water, it will fall through. Depending on its size, it will either sink or float.
Water tension is a good variable to add to your answer.