• Bring your 2026 application questions to our open office hours with Emil Chuck, PhD, Director of Advising Services for HPSA, and get them answered live. Personal statements, secondaries, interview prep, school list strategy. Sunday, May 17 at 9 p.m. Eastern.

Pendulum PE question

Started by sanguinee
This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.

sanguinee

Full Member
7+ Year Member
Advertisement - Members don't see this ad
Can someone better explain why the velocity is not increasing if both KE and PE are increasing due to the increase in mass?

Screen Shot 2015-01-17 at 12.07.09 PM.png
Screen Shot 2015-01-17 at 12.07.05 PM.png
 

Attachments

  • Screen Shot 2015-01-17 at 12.07.05 PM.png
    Screen Shot 2015-01-17 at 12.07.05 PM.png
    60.6 KB · Views: 97
  • Screen Shot 2015-01-17 at 1.29.40 PM.png
    Screen Shot 2015-01-17 at 1.29.40 PM.png
    130.1 KB · Views: 110
If you look at it mathematically, it's because at that lowest point of maximum velocity, all of the potential energy (mgh) has been converted into kinetic energy (1/2 mv^2). So we have mgh=1/2 mv^2, and m cancels out of the equation. Does that help?