Final answer:
Diagram C, where the upward force is 3.1N and the downward force is 1.8N, represents the raindrop that is slowing down because the upward force is greater than the downward force, indicating deceleration according to Newton's second law.
Step-by-step explanation:
The question asks about assessing which of the four diagrams representing falling raindrops indicates that the raindrop is slowing down. Based on Newton's second law of motion, the acceleration of an object is the result of the net force acting on it divided by its mass. Therefore, for a raindrop to be slowing down, the upward force (air resistance) must be greater than the downward force (gravity).
Looking at the options given:
A) The upward and downward forces are equal, so the raindrop would be moving at a constant speed.
B) The upward force is less than the downward force, so the raindrop would be accelerating downwards.
C) The upward force is greater than the downward force, so the raindrop would be decelerating or slowing down.
D) The upward force is less than the downward force, so the raindrop would be accelerating downwards.
Therefore, the correct answer is C) the third diagram with an upward force of 3.1N and a downward force of 1.8N.