Physics 8.5 Rotational Kinetic Energy (18 of 19) Mass Hanging From a Rotating Disk

In this video I will find the v(final)=? of a m=2kg mass “falling” 3m attached to a rotating solid disk of R=30cm, M=4kg.

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[oliviagreen]

Thank you, thank you, thank you! You helped me ace a homework problem I was struggling with.

[umiturgutaswwsa]

Thank you for teaching me physics.I will enter my final exam in 3 hours and I feel pretty confident about phy even though my calculus exam went bad

[pranavamali]

A collective thnku for all ur previous videos😊

[ptyptypty]

WHOA.. Hi Michel, have you ever heard the expression: "There's more than ONE WAY to Skin a Cat?" don't get me wrong, I'm a Cat lover... lol, but I tried another method, just for fun, and found that I could arrive at the same answer by using, Vf^2 -Vo^2 = 2ah which becomes Vf^2 = 2ah. Then I found out what "a" was, (from one of your other videos) and then inserted the values... "a" = mg/(m + (1/2) M) and Voila... came up with the same answer!! :D That other video was entitled "Application of Moment of Inertia (5 of 11) Object hanging from rotating disk" Pretty Cool, eh? :) One other last thought, That equation I used is derived from the WORK Equation = Delta KE, so it's still all about ENERGY!!.. that reminds me, I have to pay my Electric Bill.... See ya! :)

[ptyptypty]

my calculator quit working, so it took me alot longer, (2 days) to do the math using my SLIDE :D wow, those were the GOOD OL' DAYS! :D

[jeetendrasharma]

Sir, as disc is located at certain height above ground level, it will also have potential energy. Why it is not considered while forming the energy equation. Though it remains constant initially and finally and will get cancelled out in energy equation. Pls explain.

[Delta-lghh]

Is the tangential velocity of the spinning disk the same as the velocity of the falling block? I missed this relationship on a test

[jeetendrasharma]

Sir, can I post a question to you for providing solution, under 'Viewer's request.

[ClementineJouontso-rovi]

Excuse me sir why is energy final" Ket + Ker"? Given that the disk and the mass will be static at the end of motion

[erc]

Why is there no final potential energy if the block hasn't hit the floor yet?