Vertical energy of a pendulum - is there one?

[jojotank]

Homework Statement

Hello. I was just wondering. You have a simple pendulum . string and a ball with mass at the end. We usually solve examples and we think about conversation of kinetic energy and potentional energy. I was just wandering if there is also something like vertical kinetic energy. Or it is just a part of kinetic energy itself (just the sine part of velocity vector). If it exist, i know it is very small. I was just wondering... Thank you.

Homework Equations

no need for them

The Attempt at a Solution

thinking

 

[Doc Al]

Not quite sure what you mean. You can certainly express the velocity of the pendulum in terms of vertical and horizontal components, but the kinetic energy uses the full velocity. Velocity has a direction, but kinetic energy does not.

 

[jojotank]

It is totaly clear now. Thank you.