Derive Equation for Velocity as Function of Time - Help Integrating

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In summary, the conversation discusses deriving an equation for an object's velocity as a function of time, with consideration for mass varying with time. The derived equation is a=-(kvo/m), where k represents the rate of change of mass and vo represents the velocity of escaping gas. The conversation also explores the units and suggests using integration to find the final equation for velocity in relation to mass.
  • #1
Punkyc7
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Homework Statement


Derive an equation for an objects velocity as a function of time


Homework Equations



i have that a=-(kvo/m)

The Attempt at a Solution


so i get dv/v=-(k/m)dt then i get
1/v= -kt/m +C and then I am stuck
 
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  • #2
It's been awhile, but I think the integral of dv/v is the natural log of v. Then you can probably exponentiate both sides
 
  • #3
so
lnv= ln(-kt/m +C)
then
e^lnv=e^ln(-kt/m +C)
so is this right
v=e^ln(-kt/m +C)
 
  • #4
you only have the 1/v on the left side:

lnv= (-kt/m +C)

e^lnv=e^(-kt/m +C)
so is this right
v=e^(-kt/m +C)

yeah, that seems about right. I'm a little worried about the units, maybe you can do something with that k or C...
 
  • #5
a=-(kvo/m)
The above relation represent rocket equation where vo represents the velocity of escaping of gas which is constant an k represents dm/dt, the mass of fuel ejected per unit time. It is also constant. Here mass of the fuel is varying with time.
So you can find the velocity of the object with respect to mass rather than the time.
a = dv/dt = - (dm/dt)vo/m
dv = -vo(dm/m). To find the velocity take the integration between the limits m = Mo to m = M.
 

FAQ: Derive Equation for Velocity as Function of Time - Help Integrating

What is the purpose of deriving an equation for velocity as a function of time?

Deriving an equation for velocity as a function of time allows us to mathematically describe the relationship between an object's velocity and time. This can be helpful in understanding the motion of objects and predicting their future positions.

How do you integrate to derive the equation for velocity?

To derive the equation for velocity, we use the fundamental theorem of calculus to integrate the acceleration function with respect to time. This will give us the velocity function, which represents the rate of change of an object's position over time.

What are the key steps in deriving the equation for velocity as a function of time?

The key steps in deriving the equation for velocity are: identifying the acceleration function, integrating the acceleration function with respect to time, applying any initial or boundary conditions, and simplifying the resulting equation to solve for velocity.

Can the equation for velocity as a function of time be used for all types of motion?

Yes, the equation for velocity as a function of time can be used for all types of motion, including linear, circular, and projectile motion. However, the specific equation may vary depending on the type of motion and any external forces acting on the object.

How can the equation for velocity as a function of time be used in real-world applications?

The equation for velocity as a function of time has many real-world applications, such as calculating the speed and position of moving objects, predicting the trajectory of projectiles, and understanding the motion of celestial bodies. It is also used in engineering and physics to design and analyze various systems and structures.

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