How can i make a graph of velocity vs time taking into account air resistance?

In summary: No, your graph will be above the x-axis.Ok thanks for answering but i have one more question Wil my curve be above the x-axis or below like this...No, your graph will be above the x-axis.In summary, to create a graph of velocity vs time for an object falling from rest, take into account air resistance. At low speeds the air resistance is a linear function of speed and at higher speeds it is proportional to the square of the speed. Eventually the resistance builds up so that it is equal to the body's weight. What happens to the speed then?
  • #1
nnis13
25
0
How can i sketch a graph of velocity vs time for an object falling from rest taking into account air resistance.

Will it be a curve ?

How can i do it?
 
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  • #2
nnis13 said:
How can i sketch a graph of velocity vs time for an object falling from rest taking into account air resistance.

Will it be a curve ?

How can i do it?
At low speeds the air resistance is a linear function of speed and at higher speeds it is proportional to the square of the speed. Eventually the resistance builds up so that it is equal to the body's weight. What happens to the speed then?

AM
 
  • #3
Andrew Mason said:
At low speeds the air resistance is a linear function of speed and at higher speeds it is proportional to the square of the speed. Eventually the resistance builds up so that it is equal to the body's weight. What happens to the speed then?

AM

I am new to physics so i don't understand very much so can you please explain in a bit more detail or provide a link that shows a graph of this type please ?
 
  • #4
nnis13 said:
I am new to physics so i don't understand very much so can you please explain in a bit more detail or provide a link that shows a graph of this type please ?
To being, draw the velocity time graph of a body falling due to gravity without resistance. That will be a line v = at where a = g to begin. As velocity increases, resistance increases so a gets smaller. So what happens to the graph? Does the graph get steeper or flatter? At some point, the resitance is equal to the force of gravity. What happens to the graph at that point?

AM
 
  • #5
Andrew Mason said:
To being, draw the velocity time graph of a body falling due to gravity without resistance. That will be a line v = at where a = g to begin. As velocity increases, resistance increases so a gets smaller. So what happens to the graph? Does the graph get steeper or flatter? At some point, the resitance is equal to the force of gravity. What happens to the graph at that point?

AM

At a point where resitance is equal to the force of gravity i think that it will be 0 acceleration but constant speed but how can i draw this ??

Will it look like this > http://www.juniata.edu/faculty/roth/QM/Images/incConcUpLabel.gif

or like this http://www.juniata.edu/faculty/roth/QM/Images/decConcDownLabel.gif

By the way thanks a lot for answering
 
  • #6
nnis13 said:
At a point where resitance is equal to the force of gravity i think that it will be 0 acceleration but constant speed but how can i draw this ??

Will it look like this > http://www.juniata.edu/faculty/roth/QM/Images/incConcUpLabel.gif

or like this http://www.juniata.edu/faculty/roth/QM/Images/decConcDownLabel.gif

By the way thanks a lot for answering
Let's say at t=15 seconds the acceleration is 0 and its speed,v, is 60 m/s. Plot that point on the graph. Now at t=16 seconds, what is v? At t=17, 18, 19, 20...? Connect those points. What does the graph look like?

AM
 
  • #7
Andrew Mason said:
Let's say at t=15 seconds the acceleration is 0 and its speed,v, is 60 m/s. Plot that point on the graph. Now at t=16 seconds, what is v? At t=17, 18, 19, 20...? Connect those points. What does the graph look like?

AM
from 1-15 it will be a curve abd then from 16s until it hits the ground will be a straight line parallel to the x-axis ?

i am not sure about that but that's how i understood it
 
  • #8
nnis13 said:
from 1-15 it will be a curve abd then from 16s until it hits the ground will be a straight line parallel to the x-axis ?

i am not sure about that but that's how i understood it

So is that right ?

That's what will look like ??
 
  • #9
nnis13 said:
So is that right ?

That's what will look like ??

Yes, that's right. However, note that in theory, acceleration is never zero; the speed of an object approaches a certain speed (called terminal velocity) as the force of air resistance becomes closer and closer to the force of gravity, but never quite reaches it. So draw your graph as a smooth curve; don't include any jumps or pointy vertices.
 
  • #10
ideasrule said:
Yes, that's right. However, note that in theory, acceleration is never zero; the speed of an object approaches a certain speed (called terminal velocity) as the force of air resistance becomes closer and closer to the force of gravity, but never quite reaches it. So draw your graph as a smooth curve; don't include any jumps or pointy vertices.

Ok thanks for answering but i have one more question
Wil my curve be above the x-axis or below like this http://www.juniata.edu/faculty/roth/QM/Images/decConcDownLabel.gif
 
  • #11
I suppose you mean the t-axis, since this is a v vs. t graph. Think about it. Should velocity change faster as time passes, or should it change slower?
 
  • #12
ideasrule said:
I suppose you mean the t-axis, since this is a v vs. t graph. Think about it. Should velocity change faster as time passes, or should it change slower?

Yes the t-axis velocity changes slower i think
 

1. How do I determine the velocity of an object with air resistance?

The velocity of an object with air resistance can be determined by using the equation v = v0 - gt, where v0 is the initial velocity, g is the gravitational acceleration, and t is the time. This equation takes into account the decreasing velocity due to air resistance.

2. Can I use the same graphing techniques for velocity vs time with and without air resistance?

No, the graphing techniques for velocity vs time will be different for objects with and without air resistance. When air resistance is present, the velocity will not increase linearly with time, so the graph will show a curve rather than a straight line.

3. How does air resistance affect the shape of the velocity vs time graph?

Air resistance will cause the velocity vs time graph to have a curve instead of a straight line. This is because as the object moves, the force of air resistance increases and causes the object's velocity to decrease at a faster rate.

4. Are there any other factors that should be considered when graphing velocity vs time with air resistance?

Yes, in addition to air resistance, other factors such as the shape and size of the object, the density of the air, and the object's mass can also affect the shape of the velocity vs time graph. These factors can be accounted for by using more advanced mathematical equations.

5. Can I use a computer program to make a graph of velocity vs time with air resistance?

Yes, there are many computer programs and software that can help you create a graph of velocity vs time with air resistance. These programs often have built-in equations and tools to account for air resistance and other factors, making it easier to accurately represent the data.

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