Recent content by AlonZ

What's troubling me is how does a particle at rest has frequency different than 0, as you said w>0. I'm attaching a file so you can see exactly where my problem is. if lambda goes to infinity, doesn't frequency has to go to zero? As it does not in the attached photo. Thanks a lot for the...

Hi there, I'm a bit confused about the E=hf equation for mass particle(f for frequency), and Lorentz Invariant (E^2 -p^2c^2=m^2c^4). The question is, which energy is it? Total Energy- Kinetic plus Rest, or only kinetic energy. Now, if it's total energy, then you get that a particle at rest...

alright think I'm getting the idea.. Thx for the help

I see your point, my thought was that if the pendulum reaches the small loop's highest point and still has the tiniest amount of energy it'll not fall. Still a bit hard for me to understand why that is wrong.

yes, as you can see, the red circle is a new pivot for the pendulum. once the rope hits the red pivot, it spins around it and with enough velocity, completes a loop. the question is what should be the minimum angle from which I'd have to drop the pendulum for it to complete that loop.

the expression for the height of the pendulum before the drop, you can see at the SS I sent

that's why I say mgL(1-cos(a) ) > mg2l, once it's larger there is still some energy left as kinetic for the pendulum not to fall

My, supposedly rational thought is that if the pendulum will drop from a height higher than the top of the loop's height, by the law of conservation of energy, it'll have enough velocity to complete the loop. The teacher's final result shows a different approach. Am I right? Wrong? Thanks