Velocity and resistance problem. diff Eq type

In summary, the conversation discusses a body moving with velocity V encountering resistance in the form of dV/dT=-k*V^(3/2). The solution to this differential equation is V(t)=(4v.)/(k*t*sqrt(v.)+2)^2, with v. being the same as v(subscript 0). The individual initially struggled to understand how to get from dv/dt to the given v(t), but later realized that integrating and solving for the constant C would lead to the correct answer. They then mention verifying the solution by setting t=0 and solving for v. before plugging in the constant C.
  • #1
jd1828
44
0
A body moving with velocity V enounters a resistance in the form of dV/dT=-k*V^(3/2). Show that

V(t)=(4v.)/(k*t*sqrt(v.)+2)^2
v. is the same as v(subscript 0)


When i solve the differential equation i keep getting V(t)=4/(k*t-v')^2

I have no idea how to get from dv/dt to the given v(t)
 
Physics news on Phys.org
  • #2
try an intergal
 
  • #3
oh wow I would have never though to that!

since i figured it out on my own, you verify from v(t) that v(0)=v. solve the diff eq then set t=0 and set it = to v. solve for constant C sub back into equation and get the anwser.
 

1. What is the relationship between velocity and resistance in a differential equation?

The relationship between velocity and resistance in a differential equation is described by Newton's Law of Motion, which states that the acceleration of an object is directly proportional to the net force acting on the object and inversely proportional to its mass. In simpler terms, an increase in resistance will result in a decrease in velocity.

2. How does the presence of resistance affect the solution of a differential equation?

The presence of resistance in a differential equation can significantly impact the solution. It can alter the shape of the solution curve and lead to a different steady-state solution. In some cases, the presence of resistance can even cause the solution to diverge or oscillate.

3. Can the resistance in a differential equation be negative?

No, resistance in a differential equation cannot be negative. Resistance is a physical quantity that represents hindrance or opposition to motion, and it can only have positive values. A negative resistance value would not have any physical meaning.

4. How do initial conditions affect the solution of a differential equation with velocity and resistance?

Initial conditions, such as the initial velocity and position, play a crucial role in the solution of a differential equation with velocity and resistance. They determine the specific solution curve that satisfies the given equation and can significantly impact the behavior of the solution over time.

5. What are some real-life examples of systems that can be modeled using a velocity and resistance differential equation?

Some examples of systems that can be modeled using a velocity and resistance differential equation include the motion of a car through air resistance, the movement of a pendulum through friction, or the flow of a fluid through a pipe with resistance. These systems can be found in various disciplines, such as physics, engineering, and biology.

Similar threads

  • Advanced Physics Homework Help
Replies
4
Views
1K
  • Advanced Physics Homework Help
Replies
0
Views
287
  • Advanced Physics Homework Help
Replies
7
Views
1K
Replies
3
Views
1K
  • Advanced Physics Homework Help
Replies
6
Views
2K
  • Advanced Physics Homework Help
Replies
4
Views
3K
  • Advanced Physics Homework Help
Replies
1
Views
767
  • Introductory Physics Homework Help
Replies
7
Views
265
Replies
10
Views
683
  • Advanced Physics Homework Help
Replies
1
Views
711
Back
Top