What is the net force acting on a 25N freely falling object. What is the net force when the object encounters 15 N of air resistance. When it falls fast enough to encounter 25 N of air resistance?

Answer 1

You call it a "25N object". Where did it get that label ? It must be because

when it's down on land, not freely falling, and you put it on a bathroom scale,

the scale reads "25N". When you see that, you know that the mutual forces

of gravity in both directions between the object and the Earth are both 25N,

and for convenience, you begin to refer to that object as a "25N object".

As long as the distance between the object and the center of the Earth remains

pretty much the same, so does the gravitational force between them. With that

knowledge, we can go on and answer your question.

First, the "freely falling" bit. An object plowing through air is not freely falling,

because it has to keep pushing air molecules out of its way. Since you call the

object a "freely falling" one, we know that there is no air in its path, and there

are no springs, weights, bungee cords, people, or rays of mysterious radiation

exerting other forces on it. It's just freely falling, somewhere near the surface of

the Earth. And since the only force on it is the force of gravity, the magnitude of

the force is that old 25N again, acting in the direction that we call "down".

Answer 2

The direction is downwards i.e. towards the center of the earth.

Answer 3

25 n, 10 n, 0 n

Answer 4

net force=25-15=10N

Answer 5

7-N

Answer 6

10

Answer 7

7n