1.act against the direction of motion and gets larger as an object moves faster

2. an object acted upon by a net force will accelerate in the direction of that force.
3.the speed an object reaches when the force of gravity is balanced by the force of air resistance

duplicate post.

1. The force described in the first statement is called friction. Friction always acts against the direction of motion and increases as an object moves faster. To understand why it gets larger as an object moves faster, you can conduct a simple experiment. Place a book on a table and try to slide it. You will notice that it is relatively easy to move the book slowly, but as you try to move it faster, you will feel a stronger force that resists motion. This force is friction and it depends on the type of surface and the force pushing the objects together.

2. The second statement describes Newton's second law of motion, which states that the acceleration of an object is directly proportional to the net force applied to it and inversely proportional to its mass. In simpler terms, if you apply a force to an object, it will accelerate in the same direction as that force. The amount of acceleration depends on the magnitude of the force and the mass of the object.

To calculate the acceleration, you can use the formula:
acceleration = net force / mass

For example, if you apply a net force of 10 Newtons to an object with a mass of 2 kilograms, the acceleration would be:
acceleration = 10 N / 2 kg = 5 m/s^2

3. The third statement refers to the concept of terminal velocity. Terminal velocity is the maximum velocity that an object can reach when the force of gravity pulling it downward is balanced by the force of air resistance pushing it upward. Initially, when an object is falling freely, the force of gravity is greater than the force of air resistance, so the object accelerates. However, as the object gains speed, the force of air resistance increases until it equals the force of gravity. At this point, the object stops accelerating and reaches its terminal velocity.

The value of terminal velocity depends on several factors, such as the shape, size, and weight of the object, as well as the density and viscosity of the fluid (in this case, air). For example, a skydiver in a spread-eagle position will have a higher terminal velocity than a skydiver in a tight ball position.

To calculate the terminal velocity, detailed knowledge of fluid dynamics and precise measurements are required. Various formulas and models exist based on empirical data. However, in most cases, it is sufficient to know that an object's terminal velocity is the speed at which the force of gravity is balanced by the force of air resistance.