Kinetic Energy in Polar Coordinates (8.4)

In this video, I derive the kinetic energy in polar coordinates, pursuant to the study of planetary motion.

[jameyatesmauriat]

Very awesome and exhausting work, thank you so much and wish you very long life and success.

[barneyronnie]

Your explanations emphasize clarity by attention to details and clear explanations! Great job, sir!

[ruthanderson]

I think you missed out the derivative of psi on the cross product, isn't supposed to be -2r'r psi' sin psi cos psi? same goes with the +2r'r psi' sin psi cos psi I know it eventually cancels out and I doesn't really matter but I thought I point it out since I thought I missed out on something

[grahamflowers]

There is no kinetic energy in a moving mass there is force Mv squared, kinetic energy is the energy of consistent work from a consistent force regards Graham Flowers

[veronicanoordzee]

Nice math, but not very intuitive. Next time, also draw an ellips and two velocity-vectors. Their dependence on r and phi are then easily seen.