The discussion revolves around a pendulum problem where the bob is pulled to one side and released, leading to questions about the height it reaches on the opposite side after swinging. The original poster expresses confusion about why the height on the right side is equal to the original height when the pendulum is released.
The discussion is ongoing, with participants providing guidance on the relationships between energy forms and questioning the original poster's understanding of kinetic energy at different points in the pendulum's swing. There is no explicit consensus yet, but there are productive lines of questioning being explored.
Participants are navigating the implications of energy conservation in the context of the pendulum's motion, with some uncertainty about the initial conditions and the resulting velocities at key points in the swing.
berkeman said:The relevant equations have to do with kinetic energy KE, potential energy PE, and total energy TE.
Show us the equations, and tell us how they could be interpreted to give you your answer.
roxxyroxx said:KE = 0.5mv^2
PE = mgh
TE = 0.5mv^2 + mgh
= mv^2 + gh
berkeman said:Good start. (Not sure what you mean by the last line, but the other lines are correct.)
Now, what common characteristic does the ball have when it is first released, and when it stops at the top of its arc after the string contacts the peg? What is the KE in each of those two cases? Answer that, and then answer the whole problem!
roxxyroxx said:umm I am not 2 sure but:
mgh = 0.5mv^2 + mgh
??