Velocity as a function of time -- Terminal Velocity

Click For Summary
The discussion revolves around solving a differential equation related to terminal velocity using Euler's method in Python. The user is confused about how to derive the velocity function v(t) from the given equation dv/dt = a - bv, emphasizing the need to first understand the differential equation rather than directly seeking v(t). It is clarified that the user will not find a direct v(t) equation but will need to apply Euler's method to the existing dv/dt equation. The importance of familiarizing oneself with Euler's method is highlighted as a crucial step before coding the solution. Understanding these concepts is essential for successfully completing the assignment.
alex steve
Messages
5
Reaction score
0
I am having trouble finding a staring place. My class requires us to use python to solve the equation.

This problem requires me to use eulers method to solve it. My issues is that i am getting confused as of how to find the v(t). Its been a while since i have had to do advance physics like this. Any help would be appreciated.

The question asks:

When jumping from an airplane, you will most often have a parachute to slow your fall. Here let's consider a very simple example in which the frictional drag force is linearly dependent on the velocity:dv/dt=a−bvwhere a and b are constants. In our case a corresponds to the acceleration due to gravity, and b is a constant from drag. Note that the drag force is negative, indicating it opposes the motion. Use the Euler method to solve for v as a function of time and plot your results. A convenient choice of parameters is a=10and b=1. You should find that v approaches a constant value at long times: this is the terminal velocity. If you open your chute immediately after jumping from the plane, you will have vinitial∼1 m/s, but if you wait a minute or so, you will have vinitial∼50 m/s. Plot both v(t) curves on the same plot with a legend.

I am just getting confused with : if the equations says dv/dt = a=bv , where would i insert t for v(t) if the equation has no t except for the dt in the denominator.
 
Physics news on Phys.org
Please don't delete the homework template.
alex steve said:
I am just getting confused with : if the equations says dv/dt = a=bv , where would i insert t for v(t) if the equation has no t except for the dt in the denominator.
It is a differential equation, you have to solve it first.
 
alex steve said:
I am just getting confused with : if the equations says dv/dt = a=bv , where would i insert t for v(t) if the equation has no t except for the dt in the denominator.
First, what do you know about Euler's Method?
 
I do not need to know about Euler's method right now . I just need help on figuring out the v(t) equation which is the first step of this problem. I will have to code The euler's method later on.
 
alex steve said:
I do not need to know about Euler's method right now . I just need help on figuring out the v(t) equation which is the first step of this problem. I will have to code The euler's method later on.
You won't have a v(t) equation. You'll have a dv/dt equation (which you already have). Then you'll apply Euler's Method to that. So you really should read up on Euler's method first. A web search should turn up many references and examples of its application.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

Similar threads

  • · Replies 7 ·
Replies
7
Views
1K
Replies
10
Views
1K
Replies
7
Views
580
  • · Replies 3 ·
Replies
3
Views
2K
Replies
3
Views
1K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K