# Pendulum Conservation of Energy

PeroK
Homework Helper
Gold Member
2020 Award
L minus cos(theta)L

Where are you getting ##\theta_{max}## from?

spsch
Where are you getting ##\theta_{max}## from?
Theta is usually given, it differs from problem to problem

PeroK
Homework Helper
Gold Member
2020 Award
Theta is usually given, it differs from problem to problem

You need to post a problem. Show your calculations and we can see where you are going wrong. You seem to understand everything so I don't know what it could be!

spsch
You need to post a problem. Show your calculations and we can see where you are going wrong. You seem to understand everything so I don't know what it could be!
thanks. yeah it seems like i've been making some algebra mistakes. just seemed so unlikely by the amount of problems i've tried. But experience tells me there is no limit to dumb mistakes.

I'll try again tomorrow (I don't have the books with me here) and post if i continue to get it wrong.

Thank you very much, so sorry for being difficult!

FactChecker
Gold Member
it seems like i've been making some algebra mistakes. just seemed so unlikely by the amount of problems i've tried.
That's exactly when they start happening again -- and in the parts that one is very confident of and doesn't think about enough.

spsch
You need to post a problem. Show your calculations and we can see where you are going wrong. You seem to understand everything so I don't know what it could be!
Hi, so I tried again. I think I'm using the calculator wrong.
When I use √2gΔh = v that still doesn't work out.
But if I use a correct value for v, square it and divide it by 2 I get gΔh. So mgΔh is 1/2mv2 after all. I'm so relieved. Sorry for the trouble. And thank you all for helping me!

haruspex