😭😭😭

You are welcome. Keep up with the physics! Cheers, Dr. A

Thank you kindly! Cheers, Dr. A

To my #1 Fanderson, you're welcome. Cheers, Dr. A

I first read it 'work done on the explanation and proof' physics has done its job

That's the goal. Cheers, Dr. A

+Migue Figueroa I get it, "clear" explanation. Very punny. Thanks for watching! Cheers, Dr. A

password 69 ffg

Math adventures, Excellent! Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A

+MrCyphox You're welcome. Good luck on the midterm. Cheers, Dr. A

+Justin Edwards You're welcome. Keep with the physics! Cheers, Dr. A

Thanks for watching. Cheers, Dr. A

EpmMaxim, You're very welcome. Glad you're enjoying the videos. You might also like my new site: www.universityphysics.education Cheers, Dr. A

+Noah Meyer Thanks for the props Noah! I did not have to write everything backwards. See this link: kzfaq.info/get/bejne/eb14gNeEs7HciXU.html Cheers, Dr. A

LOL

Because it is treated as a simple a point mass, and its size is insignificant. You can calculate what 1/2*I*omega^2 is, for a point mass on a negligible mass rod of length L, and you will find that 1/2*I*omega^2 also equals 1/2*m*v^2.

Nope. I let the software do the inversion. Check it out here: www.learning.glass Cheers, Dr. A

No, for work to be done there must be some displacement (W=F.∆d). As tension acts along the radial axis, and the pendulum's distance from the centre does not change, tension does no work.

Your words are right, but the math is wrong. Initial kinetic energy is zero. But final potential energy is also zero. If h is the height at which it started, relative to the bottom of the swing, then you just get mgh=1/2 mv^2. See the 2:20 mark. Cheers, Dr. A

The purpose of the tension is two-fold, for a pendulum. 1. It needs to oppose the radially-outward component of gravity 2. It needs to cause centripetal acceleration to keep the bob following a circular path To solve part 1, it needs to at least be as large as m*g*cos(theta). To solve part 2, we also need to add onto it, m*v^2/L This means, that in total, the tension will equal: Ft = m*(g*cos(theta) + m*v^2/L) given a simple pendulum with a bob mass of m, a length L, and in a uniform gravitational field of g. The values of theta and v are transient throughout this problem, since v is greatest when theta is zero, and v is zero when theta is at its max. So you would determine v as a function of theta through conservation of energy, in order to get a concise expression for Ft in terms of theta.

Believe it or not, it's something called "Jerk": en.wikipedia.org/wiki/Jerk_(physics) Cheers, Dr. A

Because that isn't the center of mass. The mass is assumed to be concentrated in the ball, and the string has negligible mass.

That's a great question and quite a tough one to answer. But you're absolutely right, friction and air resistance will cause it to stop eventually. Maybe I'll make a video about it. Cheers, Dr. A

@@yoprofmatt Thanks Doc A. I have been pre-occupied with this idea as the same with the UNDAMPED condition with the RLC circuits both SERIES and PARALLEL, I just can't make the PHYSICS connection of the 3 DAMPING factors involved... Please show all the MATHEMATICAL STEPS going though the mathematics. Than You for Your Response.

@@yoprofmatt I just want to know the difference of both angles in respect of gravity but according to you/physics, it is nothing to do but the friction and air resistance. So it means the friction and air resistance are the important things to eliminate to get the pendulum swing longer? Thanks for the answer 🙏

In the second case, the pendulum bob is at its highest point, thus also at rest (v=0) hence no kinetic energy. Cheers, Dr. A

Clear glass. Check it out here: www.learning.glass Cheers, Dr. A

Come see us here: www.learning.glass Cheers, Dr. A

It's always the same: mg down. Cheers, Dr. A

+Daniel Gurman Not exactly. It's an image flip. See kzfaq.info/get/bejne/eb14gNeEs7HciXU.html Cheers, Dr. A

no they use a mirror to reflect it

Glad to hear it. Keep up with the physics! Cheers, Dr. A

And to you! Cheers, Dr. A

No daaaaamn. Physics trick: kzfaq.info/get/bejne/eb14gNeEs7HciXU.html Cheers, Dr. A

Conservation of energy. No energy can be created nor destroyed, it can only be converted into other forms of energy.

ohhh thank u so much!😄

Luke Caetano, Thanks, love you too. You might also like my new website: www.universityphysics.education Cheers, Dr. A

@@yoprofmatt I'm an aerospace engineer touching up for statics next semester so will do!

The Pendulum starts at an initial height h. Which is also Ei = mgh. Ef is when it's at the bottom so you are correct 1/2 mv^2 is when it's the bottom but were confused about Ei and Ef it seems

Tried it again and still got the same answer. Did you use sin instead of cos? Cheers, Dr. A

Calculator was in radians, always worth a check to make sure :) When in degrees we get 1

Excellent, thanks for the update. Cheers, Dr. A

@@yoprofmatt When I am in degrees, I get .317, when I am in radians, I get .99.

Dr Lucky, Thanks for the comment. In physics we like to talk about theories that relate to experimental predictions and ultimately experimental results. If we cannot test it, it's not physics. Since all the energy in our universe was released by the Big Bang, you might say that the Big Bang "created" energy. But that would imply that you could see what was there before the Big Bang. And unfortunately, we have no way of seeing anything before the Big Bang. Thus that does not qualify as physics. So this is our current understanding: The total energy in the universe is a fixed quantity. We cannot create more, nor destroy it. We can simply move it around. Cheers, Dr. A p.s. Physics, like all science, is constantly evolving. Just because our current understanding is this does not mean our future understanding will be the same.

Dr Lucky, I don’t believe energy can be created, it can only be changed in form. At least on earth. But I also believe that our knowledge of physics has us stuck in a box. Although I believe we are 90% correct, there are things we do not know. Perpetual motion is not possible, however there are ways to use physics and combining known forces to convert energy. So extended motion is a factual thing, just look down at the rotating earth. So I believe that some day we will find a way to get over unity without defying physics, and maybe even leaving the laws of thermal dynamics in tact. But it seems that our teachings are holding us back.

Me or the pendulum? Cheers, Dr. A