Since an unrelaxed string is attached to the block, there is a tension force on it. Depress mouse to view answer. Normal is Absent. Since the block is not supported by any surface, there is not a normal force on it. Depress mouse to view answer.
Friction is Absent.
Since the block is not in contact with another surface, there is not a friction force on it. Depress mouse to view answer. Air Resistance is Absent. Since the object is not moving relative to the surrounding air, there is not an air resistance force on it. A block hangs from the ceiling by a spring.