How Is Velocity Expressed as a Function of Position with Given Power Input?

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SUMMARY

The discussion focuses on deriving the velocity of a vehicle as a function of position given a power input expressed as αx^(1/2), where α is a constant and x is the distance from the starting point. The relationship between power (P) and kinetic energy (KE) is established through the equation P = d(1/2 mv^2)/dt, leading to the manipulation of terms to express velocity in terms of position. The key insight provided is the substitution of dv/dt with dv/dx * v, which is essential for solving the resulting differential equation for v(x).

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  • Understanding of basic physics concepts, particularly kinetic energy and power.
  • Familiarity with differential equations and their applications in motion analysis.
  • Knowledge of calculus, specifically derivatives and their physical interpretations.
  • Experience with algebraic manipulation of equations in physics.
NEXT STEPS
  • Study the derivation of velocity as a function of position in classical mechanics.
  • Learn how to solve first-order differential equations relevant to motion.
  • Explore the implications of power input on vehicle dynamics and performance.
  • Investigate the relationship between kinetic energy and work done on a moving object.
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Physics students, mechanical engineers, and anyone interested in vehicle dynamics and the mathematical modeling of motion.

e2e8
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Power to a vehicle moving along a track is alpha*x^1/2. No dissipation. alpha is constant x is distance from beginning of the track. zero initial velocity.
What is Velocity as function of position?

P=d KE/dt
P=d(1/2 m v^2)/dt
P=1/2 m d((dx/dt)^2)/dt
P=1/2 m 2 v dv/dt
alpha x^1/2 = 1/2 m 2 v dv/dt

And that is as far as I get. After some random manipulations I was not able to yield anything useful. Some assistance or guidance would be greatly appreciated. Thank you.

e2
 
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dv/dt=dv/dx*dx/dt = dv/dx *v.

use this in your last formula then solve the differential equation for v(x).

ehild
 

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