If an object is moving to the left and is experiencing a net force in that same direction, we can analyze what happens to its speed as the magnitude of the force decreases over time.
Since force is acting to the left, it would typically act to maintain or increase the object’s speed in that direction. However, if the force is decreasing, this means that less force is being applied over time. According to Newton’s second law of motion (F = ma), if the force decreases, the acceleration (a) will also decrease, leading to a change in the velocity of the object.
In this case, the net force is not enough to maintain the object’s speed, and as the force diminishes, it will cause the object to lose speed. Therefore, the speed of the object is: a) decreasing.
In conclusion, as the net force acting on the object decreases while it moves to the left, its speed will also decrease over time.