2 objects from the same altitude?

[egerol1]

Hello my question is this:

If we throw 2 objects which are same but their masses are different from the same altitude they drop to the land in the same time?

(We consider that the friction force is active it's not negligible

 

[gneill]

Hello my question is this:

If we throw 2 objects which are same but their masses are different from the same altitude they drop to the land in the same time?

(We consider that the friction force is active it's not negligible

Suppose that the drop altitude was high enough that both objects could each terminal velocity for a good portion of their falls. At terminal velocity a body is no longer accelerating. Draw the free body diagram for each. How do the forces add up? Is the terminal velocity the same for each?

 

[AC130Nav]

Hello my question is this:

If we throw 2 objects which are same but their masses are different from the same altitude they drop to the land in the same time?

(We consider that the friction force is active it's not negligible

You appear to be saying the two objects have the same shape, so the friction force is the same for both. In which case they do land at the same time.

 

[gneill]

You appear to be saying the two objects have the same shape, so the friction force is the same for both. In which case they do land at the same time.

No, they won't. Write the equation for forces acting and the resulting acceleration. Here's a hint: In the case where no air resistance is acting, the force due to gravity is F = m*g. The acceleration is then given by Newton's second law, so a = F/m, or a = m*g/m = g. All fine and dandy, and just what is expected: everything falls with acceleration g.

Now try the same thing only let air resistance play a part in determining the net force. Just assume that the air resistance is given by some arbitrary function, f(v). How does the result vary with mass?

 

[tiny-tim]

You appear to be saying the two objects have the same shape, so the friction force is the same for both. In which case they do land at the same time.

But the gravitational force is different.