Derivation of Kinetic Energy


by francescopadormo
Tags: derivation, energy, kinetic
francescopadormo
francescopadormo is offline
#1
Feb18-06, 05:38 AM
P: 5
Hi,

I've always tken for granted that KE=(mv^2)/2, but never seen the derivation! I think it probably comes from U= - inegral of the force, but I can't see which force to use. Any help anyone? Maybe dimensional analysis was used?

Thanks!
Phys.Org News Partner Physics news on Phys.org
Physicists design quantum switches which can be activated by single photons
'Dressed' laser aimed at clouds may be key to inducing rain, lightning
Higher-order nonlinear optical processes observed using the SACLA X-ray free-electron laser
Doc Al
Doc Al is offline
#2
Feb18-06, 06:29 AM
Mentor
Doc Al's Avatar
P: 40,889
I suspect you are thinking of the "work-energy" theorem, in which one integrates the net force on an object over the distance traveled to obtain the change in KE.

Start with Newton's 2nd law:
[tex]F = m \frac{dv}{dt}[/tex]

[tex]\int F dx = \int m \frac{dv}{dt} dx = m \int \frac{dx}{dt} dv = m \int v dv[/tex]

I'll leave the last step to you.


Register to reply

Related Discussions
HELP! ~ Mechanical Energy vs Potential Energy & Kinetic Energy Introductory Physics Homework 4
[SOLVED] Mechanical Energy vs Potential Energy & Kinetic Energy Introductory Physics Homework 3
Transformation of Kinetic and Gravitational Potential Energy:Conservation of Energy. Introductory Physics Homework 9
Derivation for Kinetic Theory of Gases Introductory Physics Homework 6
Derivation of EM Energy Classical Physics 3