Question

These four diagrams show the forces on raindrops that are falling towards the ground. Which raindrop is slowing down? First diagram both the upward and downward forces are 2.6N the second diagram, upward force of 1.4N and downward force of 1.8N the third diagram upward force of 3.1N and downward force of 1.8N and fourth diagram upward force of 0.8N and downward force of 2.6N

Answer 1

The third rain drop is the one that is slowing down.

Does a negative net force mean that the body will slow down?

Generally speaking, a body experiencing a negative net force will slow down. Newton's second law of motion states that variations in an object's motion are caused by its net force.

A negative net force indicates that the force is working against the direction of motion of the object. In this instance, the force is opposing the motion, causing a slowdown or deceleration.

We can see that in the third case, taking the downward force as positive, the net force is;

1.8 N - 3.1 N

= - 1.3 N

This means that the acceleration will also be negative and the rain drop will slow down.